Filter notifications by Organization/User

[afonsojramos]

📝 Provide a description of the new feature

Similar to Github, we could have logos in the sidebar to filter by organization. Yes, it wouldn't have the same value as GitHub, but we already group by repo, so I suppose the value is already there.

GitHub UI	Gitify sidebar

➕ Additional Information

No response

[setchy]

Now that we have collapsible headers, I wonder if we can achieve something close to this by adding a notification count badge to our headers (account and repository)

[setchy]

Something like this (or similar)...