feat(announcement): Add permission for posting announcements and new role

[amCap1712]

Introduce a new announcement.add permission to control access to announcement posting. Also, add a new role "Translation coordinator" to include this permission. Fixes #8974.

Questions:

1. I haven't updated the documentation because the name and permissions for the to be introduced "Translation coordinator" are not yet finalized. Currently, I am using the same as mentioned in the linked issue.
2. There is a dummy announcement.delete permission.

   weblate/weblate/auth/permissions.py

   Lines 530 to 531 in 6a5a25c

   	@register_perm("announcement.delete")
   	def check_announcement_delete(user: User, permission: str, obj: Model):

   I think that permission should either be merged with the announcement.add permission or converted to separate real permission.
3. There is an existing permission called announcement.edit on the global level. Should this new permission (and the delete permission) be renamed to something different to avoid confusion?

Reminder: add changelog note to run setupgroups to update role.

[nijel]

Introduce a new announcement.add permission to control access to announcement posting. Also, add a new role "Translation coordinator" to include this permission. Fixes #8974.

Questions:

1. I haven't updated the documentation because the name and permissions for the to be introduced "Translation coordinator" are not yet finalized. Currently, I am using the same as mentioned in the linked issue.

I think it is a good name, let's stick with that. ./manage.py list_permissions will generate most the access control documentation from the code.

2. There is a dummy announcement.delete permission.

   weblate/weblate/auth/permissions.py

   Lines 530 to 531 in 6a5a25c

   	@register_perm("announcement.delete")
   	def check_announcement_delete(user: User, permission: str, obj: Model):

   
   I think that permission should either be merged with the announcement.add permission or converted to separate real permission.

It grants the permission based on the announcement scope, but the question is how much is that used. Anyway, component scoped team with the announcement.delete permission would work as replacement. It just needs to be documented, as this is not something we can easily handle in the migrations. So probably having a real announcement.delete permission is a way to go.

3. There is an existing permission called announcement.edit on the global level. Should this new permission (and the delete permission) be renamed to something different to avoid confusion?

That one has name Manage announcements so probably is not that confusing. It probably should have been called announcement.manage, but I'm not sure it's worth of renaming it.

Reminder: add changelog note to run setupgroups to update role.

This is done automatically on migrate, no need to run it manually.

[amCap1712]

Updated the docs. I'll open a ticket for making announcement.delete a real permission and adding it to the translation coordinator role.