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/jspecifyOld/strictMode/UnannotatedWildcard.fir.kt

@@ -1,18 +0,0 @@
-// JSPECIFY_STATE: strict
-// !LANGUAGE: +TypeEnhancementImprovementsInStrictMode
-
-// FILE: J1.java
-import org.jspecify.nullness.*;
-
-@NullMarked
-public interface J1<T extends @Nullable Object> {
-    T foo();
-}
-
-// FILE: J2.java
-public interface J2 {
-    J1<?> bar();
-}
-
-// FILE: main.kt
-fun baz(j2: J2): Any = <!RETURN_TYPE_MISMATCH!>j2.bar().foo()<!> // Any..Any?

compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/strictMode/UnannotatedWildcard.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // JSPECIFY_STATE: strict
 // !LANGUAGE: +TypeEnhancementImprovementsInStrictMode