Multiple fixes to the SSE server
- Include the color of the tags added so the SSE server can display them
with the right color from the start
- Include the list of priorities when updating them so the SSE server
can display their human readable format rather than their rank
- Fix displaying tags added/removed when logged out
- Fix displaying assignee added/removed when logged out
- Fix refreshing live milestone updates
- Fix refreshing custom fields updates when logged out
Signed-off-by: Pierre-Yves Chibon <pingou@pingoured.fr>