[FEATURE] Desktop: Alternative options when loading a sequence already in the system

[mattdawkins]

Need someway not to have multiple duplicates of the same folder with different annotations, e.g. it detects when a folder is already loaded in the system and asks the user if they want to use the one already there or make a new one. By default using the existing one would be better to not have a situation like the below

[subdavis]

Would require coordination with #593.

In this case, again, I think a prompt is necessary. "Import new copy or open existing" would be how I'd choose to implement this.

[mattdawkins]

Either forcing there to always be one, of if there's an option for 2 need a way to differentiate between them in the recent list as well