Add shortcut hints to construction tooltips

[RED-ROSE515]

Closes #3757

Summary

• Adds a shared shortcut formatter so shortcut display text can be reused outside the keyboard shortcuts window.
• Shows configured hotkeys in construction tooltips for build, remove, rotate, and select-position actions.
• Shows the configured rotate hotkey on station construction rotate tooltips.
• Displays unbound when a tooltip action has no configured shortcut.

Testing

• cmake --build build\windows-vcpkg-check --config Release --target App
• cmake --build build\windows-vcpkg-check --config Release
• ctest --test-dir build\windows-vcpkg-check -C Release -E "Assertions" --output-on-failure