Object query & Scla 3 optimizations

[kyri-petrou]

In this PR we optimize the creation of the object query by utilizing indices instead of a Map when an object . This gives us roughly 7-8% improvement in queries that contain a lot of objects with both pure and effectful fields:

series/2.x:
[info] Benchmark                                          Mode  Cnt    Score    Error  Units
[info] NestedZQueryBenchmark.multifieldBatchedQuery1000  thrpt    5  780.252 ± 14.266  ops/s

PR:
[info] Benchmark                                          Mode  Cnt    Score    Error  Units
[info] NestedZQueryBenchmark.multifieldBatchedQuery1000  thrpt    5  832.235 ± 13.481  ops/s

Additionally, in Scala 3 we can annotate lazy vals with @threadUnsafe which compiles to a faster implementation which can be used in cases that the initialization is known to be performed by a single thread. It more or less compiles to the following:

private var fooVar = null
def foo = {
  if (fooVar == null) ???
  fooVar
}

This is OK for this usecase because we initialise the lazy val's during the call of the toType method, which is guaranteed to be performed on a single thread when we create the interpreter.