Automatically assign a valuator depending on the category

Is your feature request related to a problem? Please describe.
In the proposals component, we often find situations where proposals can be made in various categories. Typically, there is one (or more) valuator for each category to answer this proposals. Currently, the process of assigning a proposal to a valuator is done manually.

Describe the solution you'd like
This functionality is divided into three PRs (Pull Requests):

1- The process administrator can associate valuators with categories. In the initial step, it is the process administrator who has the authority to decide which valuators are assigned to each category. Multiple valuators can be associated with one category, or a valuator can be assigned to more than one category.

2- Proposals with associated categories are automatically assigned to the valuator in the same category. This eliminates the need for a manual reassignment process.

3- This functionality is complemented by an email to the valuator, notifying them of the new proposals assigned to them.

Describe alternatives you've considered

Happy to listen

Additional context

1. https://github.com/openpoke/decidim-module-reporting-proposals/issues/25
2. https://github.com/openpoke/decidim-module-reporting-proposals/pull/30
3. https://github.com/openpoke/decidim/pull/25

Does this issue could impact on users private data?

No

Funded by
This functionality has been funded by the Stadt Luzern and will be brought into the core system with funding from Pokecode