Add search bar and filters option for participants from the administration panel

ref: ED006

User story

As an admin, I want to be able to:

• search for a participant from the admin panel by name, nickname or email (the email column will be added through another contract).
• select how many participants are shown per page.

URL:
https://www.decidim.barcelona/admin/officializations

Related issues

Tasks

• add search options for a participant by name, nickname or email.
• add pagination options to select how many participants are shown per page => PR Add per_page option in Admin for participants #5480