Activity page

Hi,
I added a feature that allows you to link directly to a service's activity from the /activities page by storing the key for the service. This has been useful for me to quickly delete a  bad activity, or just to view it.

You might even be able to start dedupe already synced activities based on the ServiceKey.

Let me know what you think.

-Blake
I've had a couple cases where there is, do to duplicate activities on the service, or by Tapiriik detecting a false positive while de-duplicating. If these are stored, there could be an "Activity Doctor" feature that would tell the user there are likely the same activity on this service.