fix: system command overrides not presenting new options

[dennisrijsdijk]

Description of the Change

Change behavior of CommandManager.getAllSystemCommandDefinitions to overlay the override value over the definition's options. This allows the definition to add new options and update existing ones, and they'll be presented to the user in the system command settings UI.

Applicable Issues

#2831

Testing

Added "YYYY" date format to the "Quote Management" system command. When updating the "Quote Management" command with an existing override, the new date format now shows up in the dropdown

Ensured System Command settings still save from the edit UI

Ensured System Commands will run with the appropriate settings

Further testing requested from @CKY-