[core] Add essential unit tests for TObjArray

[ravindra-RKB]

This PR introduces essential unit tests for the TObjArray collection class to the core/cont module. It verifies common operations like appending, inserting, removing, and iterating over objects within the array, ensuring long-term stability and correctness for this fundamental container against the ROOT test framework.

Checklist

• tested changes locally
• updated the docs (if necessary)

[pcanal]

This is good start. Thanks.

[ravindra-RKB]

Thanks for the review @pcanal! I've updated the tests with:

• Checks for removing middle and last elements with RemoveAt, along with Compress().
• A TrackObject class to verify allocation/deallocation behavior between Clear() and Delete().

[github-actions]

Test Results

    24 files      24 suites   4d 6h 32m 12s ⏱️
 3 887 tests  3 846 ✅ 0 💤 41 ❌
83 204 runs  83 141 ✅ 2 💤 61 ❌

For more details on these failures, see this check.

Results for commit f71dd8c.

[ravindra-RKB]

Hi @pcanal, just a gentle ping on this. The requested test enhancements have been added and all TObjArray unit tests are passing cleanly across platforms. Whenever you have a moment, please let me know if anything else is needed or if this is ready to merge.

[pcanal]

Closing and Reopening to rebase the CI tests