Functional Test Support for Multiple Configs

[kindsun]

The GIS team is interested in testing the effects of multiple different functional test configurations as different configuration values will have different effects on the UI. For example, in #26500, we've implemented toasts which show conditionally dependent on whether a custom TMS has been configured and is available or on EMS if not reachable after a certain amount of time. One other example would be UI behavior changes dependent on whether or not EMS is enabled. With the introduction of our new GIS App, this list is likely to grow.

It looks like this may be doable (if fact I started to do it), however the scope appeared larger and with greater implications than were covered by the issue above. Happy to assist this process in any way possible, just wanted to bring it to a larger audience first!