[RobotContainer] Update controller mappings and add endgame mode boolean to dashboard

[nihonjinrxs]

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Checklist

• [x] Code is complete, and naming of variables, methods and classes are readable by non-coder humans.
• [ ] This code change has been tested and validated working as expected.
• [ ] This code change has been reflected in robot documentation in the docs folder.
• [ ] The questions below have all been answered.
• [x] The title of this PR has been updated to describe the change made, for example, [Subsystem or Command Name] Short description of change.
• [x] Assignees (usually yourself) have been assigned in the "Assignees" section to the right.
• [x] Relevant reviewers have been assigned under the "Reviewers" section at the right.

What is changing and why?

This PR makes updates to controller button mappings per the spreadsheet and adds the Endgame state from RobotState to the dashboard.

How was this tested?

Is there anything the reviewer of this PR needs to know to validate that this code is correct?

What do your team members need to know about this?