#3908 gantt page improvements

[EdgarButtner]

Changes

Changed the color legend for the Gantt page to be more mobile accessible. All changes on GanttColorLegend.tsx

Notes

Might make legend scrollable in the future. (Disappearing when mobile users scroll down)

Test Cases

No tests

Screenshots

To Do

Nothing else right now. Potentially making it scrollable in the future. (Disappearing when users scroll down)

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Closes #3908

[staysgt]

Lgtm!