Fix CombineSemanticallyEqualCatchBlocks for inner exception types

[timtebeek]

Summary

Fixes inheritance detection in CombineSemanticallyEqualCatchBlocks recipe when exception classes are inner/nested types.

Problem

The recipe was incorrectly combining catch blocks when an inner exception type (e.g., Outer.InnerException) extended a parent exception (e.g., Exception). Instead of eliminating the redundant child exception, it created invalid code:

// Before
catch (Outer.InnerException e) { }
catch (Exception e) { }

// Incorrect output (syntactically invalid)
catch (Outer.InnerException | Exception e) { }

// Expected output
catch (Exception e) { }

Root Cause

The recipe only tracked J.Identifier instances when identifying parent-child exception relationships, but inner/nested exception types are represented as J.FieldAccess in the AST (e.g., Outer.InnerException is a field access, not a simple identifier).

Changes

1. Updated data structures: Changed from Set<J.Identifier> to Set<NameTree> to handle both identifier and field access exception types
2. Enhanced exception tracking: Added handling for J.FieldAccess in addition to J.Identifier when tracking parent-child relationships
3. Improved comparison logic: Updated combineEquivalentCatches() to properly check and exclude both types of exception representations
4. Added test case: Added removeRedundantInnerExceptionWhenParentIsCaught() test that verifies the fix

Test plan

• New test removeRedundantInnerExceptionWhenParentIsCaught verifies inner exceptions are properly handled

• All existing tests continue to pass, confirming backward compatibility

• Fixes CombineSemanticallyEqualCatchBlocks doesn't detect inheritance in nested Exceptions #771

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