feat: add PicSnap to serve OpenGraph image

[wa0x6e]

Fixes #3

TODO

• Add image card for proposal
• Add image card for space
• Add generic image card
• Cache image card
• Refresh proposal image on proposal state change
• Handle emoji
• Add support for non-latin language (need fonts for each locale)

Those TODO have been scrapped, and will be raised again in another dedicated PR

• Add image card for profile Will be implemented in another issue later, as this is extra, and have no planned use. See feat: Add OpenGraph image for user profile #10
• Refresh space image on follows count update Space refresh event currently does not have trigger, as webhook service does not fire for this event type. As this will require some more complex works to detect new follows/unfollows on space, this feature is dropped from this PR, and will be raised in another dedicated issue. Space members count will be removed from image in the meantime. See feat: Refresh space OpenGraph image on follows count update #11

This PR is too big, some parts have bee extracted into these PR:

• chore: fix missing sentry capture #126
• chore: remove errors granularity #127
• chore: uncouple the cache engine from votesReport #128
• chore: retry flakky tests and add list of tests to implements #160
  Number of 'Files changes' will drop once they're merged