Profile: Activity feed improvements

[venomgfx]

At first I thought it'd be nice to have, in a user's profile, a list (or link to an endpoint) showing all voted ideas by the user. But also the liked posts, so to sum it up, the activity but with more options to filter.

Activity feed is already a feature in a profile, it's only missing a few features:

• [ ] Filter: Activity Type (liked, voted[^1], commented, etc)
• [ ] Sort: newest/oldest
• [ ] Pagination

The URL could be something like:

• https://blender.community/pablovazquez/activity or
• https://blender.community/activity/?user=pablovazquez

[^1]: Voting is currently not showing up in the activity feed, reported in #214