[FIR2IR] Consolidate type approximation

This commit gets rid of the redundant typeApproximatorConfiguration
in Fir2IrTypeConverter and uses the type approximator for captured
types instead of the manual approximation used before.

This fixes the nullability of approximated captured types, which fixes
a runtime error in WASM.

This also brings K2 IR closer to K1 IR in one test.

#KT-64261 Fixed

compiler/resolution.common/src/org/jetbrains/kotlin/types/TypeApproximatorConfiguration.kt

@@ -138,6 +138,7 @@ open class TypeApproximatorConfiguration {
         override val allFlexible: Boolean get() = true
         override val errorType: Boolean get() = true
         override val integerLiteralConstantType: Boolean get() = true
+        override val integerConstantOperatorType: Boolean get() = true
         override val intersectionTypesInContravariantPositions: Boolean get() = true
     }
 }