Write a triaging / diagnosing process for sentry errors (clientside)

Once we're tracking errors reliably we need to come up with a triaging process for sentry errors to ensure we stay on top of these issues and can schedule any required fixes for them.

We're still in the discussion phase, but when we're ready, this dshould be added to the handbook.

Questions to consider:

• Who owns this triaging process? EMs, Frontend Engineers?
• Can we split the triaging up by group?
• Can we automate the triaging like we do with our bug reports?
• Is there an existing process for backend? Can we steal borrow it?
• How do we communiucate this process once we've written it?