Add Unit Tests for IndDict

[jbolcer]

This PR adds unit tests for the IntDict class in processing/data. Resolves Issue #1108.

Changes:

• Created a new test file: IntDictTest.java
• Added 13 test cases to validate key functionality such as construction, value setting, retrieval, deletion, resizing, sorting, and checking for existence.

Coverage Results:

• Line Coverage: 51%
• Method Coverage: 44%
• Branch Coverage: 41%

All 13 test cases pass locally. Ran full test suite to ensure no regressions across the system