SizeOfList updates

[ironage]

Fix a bug when evaluating SizeListNode for Lst<Optional<Int>> type which applies to Query::size_*() methods. This is because we were instantiating BPTree where we should be using BPTree<Optional> because it stores a magic null value in the list and subtracts one from the size.

The change to SizeListNode removes one dimension of template instantiation which reduces about 200k from the release library size. The type check is now done at run time, but the benchmark added shows a negligible impact.

Req runs:    6  QueryListOfPrimitiveIntsSize (MemOnly, EncryptionOff):     min  70.96ms (-0.06%)            max  75.05ms (-1.02%)            med  72.46ms (+0.77%)            avg  72.70ms (+0.39%)            stddev  1.65ms (-8.56%)

Base monorepo branch size report:

  ./bloaty -d inputfiles ../realm-core2/build.release/src/realm/CMakeFiles/Storage.dir/*.o
    FILE SIZE        VM SIZE
 --------------  --------------
  26.3%  1.62Mi  26.9%  1.10Mi    ../realm-core2/build.release/src/realm/CMakeFiles/Storage.dir/query.cpp.o
  12.6%   794Ki  15.6%   650Ki    ../realm-core2/build.release/src/realm/CMakeFiles/Storage.dir/array.cpp.o
  11.5%   721Ki  11.4%   473Ki    ../realm-core2/build.release/src/realm/CMakeFiles/Storage.dir/list.cpp.o
   9.1%   569Ki   8.6%   357Ki    ../realm-core2/build.release/src/realm/CMakeFiles/Storage.dir/table.cpp.o
   7.1%   448Ki   5.9%   247Ki    [35 Others]
   6.8%   426Ki   6.2%   259Ki    ../realm-core2/build.release/src/realm/CMakeFiles/Storage.dir/set.cpp.o
   4.8%   299Ki   4.5%   188Ki    ../realm-core2/build.release/src/realm/CMakeFiles/Storage.dir/obj.cpp.o
   4.3%   272Ki   4.4%   183Ki    ../realm-core2/build.release/src/realm/CMakeFiles/Storage.dir/query_expression.cpp.o
   2.6%   165Ki   2.4%   100Ki    ../realm-core2/build.release/src/realm/CMakeFiles/Storage.dir/cluster.cpp.o
   2.2%   141Ki   1.9%  79.3Ki    ../realm-core2/build.release/src/realm/CMakeFiles/Storage.dir/db.cpp.o
   1.8%   112Ki   1.7%  68.9Ki    ../realm-core2/build.release/src/realm/CMakeFiles/Storage.dir/group.cpp.o
   1.7%   107Ki   1.7%  72.9Ki    ../realm-core2/build.release/src/realm/CMakeFiles/Storage.dir/sort_descriptor.cpp.o
   1.4%  90.1Ki   1.3%  54.2Ki    ../realm-core2/build.release/src/realm/CMakeFiles/Storage.dir/table_view.cpp.o
   1.3%  82.2Ki   1.2%  49.3Ki    ../realm-core2/build.release/src/realm/CMakeFiles/Storage.dir/query_engine.cpp.o
   1.2%  72.5Ki   1.2%  49.0Ki    ../realm-core2/build.release/src/realm/CMakeFiles/Storage.dir/index_string.cpp.o
   1.1%  68.6Ki   1.1%  45.6Ki    ../realm-core2/build.release/src/realm/CMakeFiles/Storage.dir/cluster_tree.cpp.o
   1.0%  63.3Ki   1.1%  45.4Ki    ../realm-core2/build.release/src/realm/CMakeFiles/Storage.dir/array_timestamp.cpp.o
   0.9%  56.0Ki   0.8%  33.2Ki    ../realm-core2/build.release/src/realm/CMakeFiles/Storage.dir/dictionary.cpp.o
   0.8%  52.5Ki   0.8%  33.2Ki    ../realm-core2/build.release/src/realm/CMakeFiles/Storage.dir/alloc_slab.cpp.o
   0.8%  50.1Ki   0.8%  34.0Ki    ../realm-core2/build.release/src/realm/CMakeFiles/Storage.dir/group_writer.cpp.o
   0.6%  35.2Ki   0.4%  17.1Ki    ../realm-core2/build.release/src/realm/CMakeFiles/Storage.dir/table_cluster_tree.cpp.o
 100.0%  6.14Mi 100.0%  4.07Mi    TOTAL

This PR:

 ./bloaty -d inputfiles ../realm-core/build.release/src/realm/CMakeFiles/Storage.dir/*.o
    FILE SIZE        VM SIZE
 --------------  --------------
  22.2%  1.32Mi  23.1%   929Ki    ../realm-core/build.release/src/realm/CMakeFiles/Storage.dir/query.cpp.o
  13.1%   794Ki  16.1%   650Ki    ../realm-core/build.release/src/realm/CMakeFiles/Storage.dir/array.cpp.o
  11.9%   721Ki  11.7%   473Ki    ../realm-core/build.release/src/realm/CMakeFiles/Storage.dir/list.cpp.o
   9.4%   569Ki   8.9%   357Ki    ../realm-core/build.release/src/realm/CMakeFiles/Storage.dir/table.cpp.o
   7.4%   448Ki   6.1%   247Ki    [35 Others]
   7.0%   426Ki   6.4%   259Ki    ../realm-core/build.release/src/realm/CMakeFiles/Storage.dir/set.cpp.o
   4.9%   299Ki   4.7%   188Ki    ../realm-core/build.release/src/realm/CMakeFiles/Storage.dir/obj.cpp.o
   4.5%   272Ki   4.6%   183Ki    ../realm-core/build.release/src/realm/CMakeFiles/Storage.dir/query_expression.cpp.o
   3.1%   186Ki   2.7%   107Ki    ../realm-core/build.release/src/realm/CMakeFiles/Storage.dir/query_engine.cpp.o
   2.7%   165Ki   2.5%   100Ki    ../realm-core/build.release/src/realm/CMakeFiles/Storage.dir/cluster.cpp.o
   2.3%   141Ki   2.0%  79.3Ki    ../realm-core/build.release/src/realm/CMakeFiles/Storage.dir/db.cpp.o
   1.9%   112Ki   1.7%  68.9Ki    ../realm-core/build.release/src/realm/CMakeFiles/Storage.dir/group.cpp.o
   1.8%   107Ki   1.8%  72.9Ki    ../realm-core/build.release/src/realm/CMakeFiles/Storage.dir/sort_descriptor.cpp.o
   1.5%  90.1Ki   1.3%  54.2Ki    ../realm-core/build.release/src/realm/CMakeFiles/Storage.dir/table_view.cpp.o
   1.2%  72.5Ki   1.2%  49.0Ki    ../realm-core/build.release/src/realm/CMakeFiles/Storage.dir/index_string.cpp.o
   1.1%  68.6Ki   1.1%  45.6Ki    ../realm-core/build.release/src/realm/CMakeFiles/Storage.dir/cluster_tree.cpp.o
   1.0%  63.3Ki   1.1%  45.4Ki    ../realm-core/build.release/src/realm/CMakeFiles/Storage.dir/array_timestamp.cpp.o
   0.9%  56.0Ki   0.8%  33.2Ki    ../realm-core/build.release/src/realm/CMakeFiles/Storage.dir/dictionary.cpp.o
   0.9%  52.5Ki   0.8%  33.2Ki    ../realm-core/build.release/src/realm/CMakeFiles/Storage.dir/alloc_slab.cpp.o
   0.8%  50.1Ki   0.8%  34.0Ki    ../realm-core/build.release/src/realm/CMakeFiles/Storage.dir/group_writer.cpp.o
   0.6%  35.1Ki   0.4%  17.0Ki    ../realm-core/build.release/src/realm/CMakeFiles/Storage.dir/table_cluster_tree.cpp.o
 100.0%  5.94Mi 100.0%  3.94Mi    TOTAL

[ironage]

Closing this one in favour of the v6 version here: #4016
When porting these changes forward, we'll have to add cases for the new data types, but the compiler should warn for missing switch cases, and the updated test covers them too.