alias-type on record and adt types

[quentin]

This pull request addresses the support of alias-types to record and adt types as discussed in #2063 and #2196 .

The central piece is skipAliasesType(type), a function that takes a type and returns an non-alias type.

Added the tests from the discussion.

[codecov]

Codecov Report

Merging #2197 (e554711) into master (1b51ae6) will increase coverage by 0.00%.
The diff coverage is 91.56%.

@@           Coverage Diff           @@
##           master    #2197   +/-   ##
=======================================
  Coverage   75.54%   75.55%           
=======================================
  Files         452      452           
  Lines       27260    27301   +41     
=======================================
+ Hits        20594    20626   +32     
- Misses       6666     6675    +9     

Impacted Files	Coverage Δ
src/ast/analysis/typesystem/TypeSystem.h	84.33% <ø> (ø)
src/ast/analysis/typesystem/Type.cpp	45.84% <50.00%> (ø)
src/include/souffle/io/ReadStreamSQLite.h	76.08% <50.00%> (-0.58%)	⬇️
src/ast/analysis/typesystem/TypeSystem.cpp	74.31% <86.84%> (-0.44%)	⬇️
...ast/analysis/typesystem/TypeConstrainsAnalysis.cpp	99.31% <100.00%> (ø)
src/ast/analysis/typesystem/TypeConstraints.cpp	90.11% <100.00%> (+0.41%)	⬆️
src/ast/transform/IOAttributes.h	97.74% <100.00%> (+0.10%)	⬆️
src/ast/transform/TypeChecker.cpp	88.68% <100.00%> (ø)
src/include/souffle/io/WriteStreamSQLite.h	69.54% <100.00%> (+0.35%)	⬆️
... and 1 more

[b-scholz]

Thanks for the contribution!