Add a "Shared with me" option when filtering projects in the search page

[lorenzo-cavazzi]

Motivation

Users can filter by owned projects, but they might have less permissive access to other projects that they want to visualize. Currently, there is no way on RenkuLab to access those projects.

Proposal

In the Author quick filters, we can add a "Shared with me" option to get all the projects for which the user has explicit permissions.
This issue is closely related to #2523 -- it's a good idea to implement them both together

[lorenzo-cavazzi]

We already have a finer-grade role filter in the Renku 2.0 search page.