Update search results view

[MGaetan89]

Move the BU selector inside the search input

Pull request

Description

This PR updates the layout of the search results to match what has been done in the other sections of the app.
It also moves the BU selector inside the search input, as it is done in pillarbox-web.

Changes made

• Put the search results inside a card
• Move the BU selector inside the search input

Screenshots

Description	Light mode	Dark mode
No content
BU selector
Results

Checklist

• Your branch has been rebased onto the main branch.
• APIs have been properly documented (if relevant).
• The documentation has been updated (if relevant).
• New unit tests have been written (if relevant).
• The demo has been updated (if relevant).
• All pull request status checks pass.