K2/Java/enhancement: implement wildcards replacement with flexible bounds

This commit in fact changes two very related places:
- first, it implements forgotten 'enhancedForWarnings' in K2 enhancement
- second, it repeats KT-48515 fix for K2 while enhancing wildcards

#KT-65594 Fixed
Related to KT-48515, KT-63746

compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/default.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // FILE: NullnessUnspecifiedTypeParameter.java
 import org.jspecify.annotations.*;