added useCallback to certain GanttChart functions

[glickgNU]

Changes

Wrapped functions related to the Gantt chart in useCallback and useMemo functions

Notes

Nothing should change in terms of functionality. However, it is difficult to test performance improvements.

Test Cases

To Do

-[ ] I Only looked at 4 files so far, however I do believe there are other relevant files that still need to be looked at related to gantt.

Checklist

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Closes # (issue #)