[feature] Bulk edit

[Churator]

Some sites require me to add several watches for different dates for example When I need to fine tune or edit, It's bit hassle to do so, I usually open all of them in new window and update each one. Maybe a bulk edit could be useful

[Hukuma1]

Just ran into this myself. I have 10+ sites in a group that share the Remove elements bit. Would love to be able to edit the whole group to have the same elements removed instead of editing one by one.

[dgtlmoon]

resolved in https://github.com/dgtlmoon/changedetection.io/pull/1610