Add custom animated tracks

[enriquetuya]

We receive multiple questions to provide the map with a vessel that is not present on the fishing tileset. The current way we are doing this is very time consuming, when it should be something quick and easy to do. We need the user to be able to upload a track in a standard format including the timestamps or at least have a way for including this on a workspace manually in an easy way.
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[nerik]

Should be easy to implement with the new tracks API

See
https://github.com/GlobalFishingWatch/GFW-Tasks/issues/886
https://github.com/GlobalFishingWatch/GFW-Tasks/issues/965
https://github.com/GlobalFishingWatch/GFW-Tasks/issues/961