test: Fixed nondeterministic test failures in testShadowModelEqualsNormalModel()

[yonghanlin]

What does this PR do?

This PR fixes a nondeterministic test failure in JavaReflectionTreeBuilderTest.testShadowModelEqualsNormalModel() within . module when running with NonDex.

Problem

The test compares CtType models built from source and from reflection (shadow models). However, both models internally use unordered collections, so the order of elements such as type members, enum values, and annotations vary between runs.

Reproduce Test

To reproduce the failure, run NonDex on . module using the following commands:

mvn -pl . edu.illinois:nondex-maven-plugin:2.1.7:nondex -Dtest=spoon.support.visitor.java.JavaReflectionTreeBuilderTest#testShadowModelEqualsNormalModel

The Fix

• Sorts and matches type members by signature (memberSignature).
• Compares enum constants by name instead of position.
• Sorts annotations by annotation type (qualified name).

[monperrus]

This PR seems too long and too complex given the severity of the problem. Is there a shorter fix as in #6500 and #6501?