fix: Changes position of menu to avoid overlap with default menu

[willum070]

The drop-down menu for changing map modes overlaps with the default control menu when it is expanded:

This PR does the following things:

• Adjusts the CSS positioning attributes to move the menu up and to the right so the menus don't conflict.
• Fixes a strict ESLint failure (no-unsafe-enum-assignment) by casting the raw DOM string to the MapModeString union type instead of the MapMode enum.