Add warning info on system configuration apply when it affects other displays (when other displays with same identifiers present)

[KrzysztofPrzygoda]

This is a follow-up to #2797.

I'd expect to be warned when changing one display system configuration would change the other one with some explanatory why and what's the follow-up to make it work.

The best process would allow to make appropriate changes in EDID directly in BetterDisplay (and during the change) to finish this operation. For example:

Changing system configuration for display A requires its EDID alternation due to the conflict with display B. There need to be changed current vendor = GSM and model = 5BBA values to different ones of your choice. Here are some suggested values that resolves this conflict in your current connected displays setup: vendor = GSN and model = 5BBB. Do you want to proceed and apply them?