Setting the PR state directly really doesn't work as it doesn't
correctly save (and can get overwritten by any dependency of which
there are many).
This caused setting odoo/odoo#165777 in error to fail, leading to it
being re-staged (and failing) repeatedly, and the PR being spammed
with comments.
- create a more formal helper for preventing directly setting computed
functions (without an actual inverse)
- replace direct state setting by setting the corresponding dependency
e.g. `error` for error and `skipchecks` to force a PR to ready
- add a `skipchecks` inverse to the PR so it can also set itself as
reviewed, and is convenient, might be worth also adding stuff to
`Batch.write`
Simplifies the `ready_prs` query a bit and allows it to be converted
to an ORM search, by moving the priority check outside. This also
allows the caller to not need to post-process the records list
anywhere near the previous state of affairs.
`ready_prs` now returns *either* the "alone" batches, or the non-alone
batches, rather than mixing both into a single sequence. This requires
correctly applying the search filters to not retrieve priority of
batches in error or targeting other branches.
