Support adding multiple plays/watches of media

[IRHM]

loosely related to #61 if we want to piggyback off of Activity to make multiple plays work. Editing activity would have to work in that case.

[IRHM]

https://github.com/sbondCo/Watcharr/issues/332#issuecomment-1920676764

https://github.com/sbondCo/Watcharr/issues/332#issuecomment-1922306036

Interesting idea using the finished activity to count as a play, it could work well for movies, but with tv shows, I sometimes go back to watching if a new season comes out, then back to finished, but wouldn't want that to count as a play (though we could add a new countAsPlay property to activity so it can be changed manually).