PR Dashboard V2

[xmo-odoo]

Current view of the batch & batch sequence (forward port) is not really clear / clearly exposed to the user.

Needs a table for the cross-info e.g.

	repoa	repob	...	current
15.0	#1234	#2345
15.2	#5435	#6546		x
16.0
16.1
16.2
master

• maybe outline line for |"current" instead
• also needs color for status (waiting, error, ready, merged)
  • direct link to failed statuses?
  • indicate whether a PR is reviewed as well (useful to know at a glance if that action is required on a PR), requested by @d-fence
• link PRs (github, probably)
• needs to show the approval chain (aka which PR were detached, which PRs where FW'd and what that spanned, ...) to make complicated fwports clearer
  • adding emphasis on showing detached PRs, as there could be multiple breaks in the same (unapproved) matrix of PRs. so there probably should be a flag / column / ... for "detached", though the r+ spans might do it? Would need to add more info to approvals to link approved PRs to their approval source...
• add a key for colors? or just word for status?

[xmo-odoo]

After working on it a bit, there are a fair number of edge cases to retrieve the base graph (the list of all PRs in the sequence) which are really annoying without reifying batches properly (aka that PRs are always members of batches, and a single one).

So unless I get a vision in th shower I'm going to punt on this as depending on #789