Add editor settings for the camera speed increase/decrease hotkeys

[adrsch]

PR Details

Just lets you change the keybinding for this in the editor settings. Defaults to the old hardcoded bindings so it should be unnoticed by most.

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My change requires a change to the documentation.
• I have added tests to cover my changes.
• All new and existing tests passed.

[Eideren]

Kind of sad that multiple keys or key combinations are not supported by that class, but that's something for another PR. Thanks !