Skip pinning animations if already running

[keianhzo]

Fixes #4059

When clicking on the pager next/prev while the previous animations os still running we use the updated object scale as the size reference and we end up with a different scaled object when the animations end.

This PR fixes just dropping animations if the previous animations are still running.

[netpro2k]

Haven't looked at this code in a long time so not sure how hard it is, but ideally we wouldn't even show the pin animation in this case. It's just an internal technical detail that the object is being re-pinned as part of paging (since its component data has changed and needs to be saved). From a user perspective they should only see the pin animation when they actually click the pin/unpin button.

[keianhzo]

@netpro2k That makes sense, I didn't really know what was the expected behavior. I've updated to not animate but I kept the code to check if the animation are already running to avoid this scaling issue in case we can get multiple events.