Add notification to valuators when a proposal is assigned

[mllocs]

:tophat: What? Why?

Sends a notification to the valuator when a proposal is assigned to them.

:pushpin: Related Issues

Closes https://github.com/decidim/decidim/issues/12909

Testing

• Assign a proposal to a valuator, the valuator receives a notification and an email. https://decidim-lot2.populate.tools/admin/participatory_processes/branch-highway/components/4/manage/
• The valuator can opt out from receiving a notification when a proposal is assigned to them. https://decidim-lot2.populate.tools/notifications_settings

:camera: Screenshots

:hearts: Thank you!

[mllocs]

This PR is on hold until https://github.com/decidim/decidim/pull/12994 is merged.

[furilo]

The notification being received is this:

Please @NilHomedes say if it's OK or we should adjust anything.

[NilHomedes]

Please @NilHomedes say if it's OK or we should adjust anything.

Yes, looks good to me. Just to clarify, the proposal-name should not be a link. So, in the notification, we only show a link to the admin panel.

I'm trying to test this, but I'm not receiving the notification email, even though I'm receiving other emails like the password recovery instructions.

[furilo]

How is your conf? (I had the same issue ;)

[mllocs]

@andreslucena ready to review 😄

[andreslucena]

@mllocs can you solve the git conflict 🙏🏽 ?

As I will not have the bandwidth to review PRs in the next few weeks, I'm assigning this review to @alecslupu.