NOTE: Must be done first: {T377186}
## User Story:
As a user I want to be able to favourite a template, so that I can reuse it without having to search for it again
## Acceptance criteria:
* Clicking on an "unselected" icon in the template search results dropdown causes a template to be added to favourites
* Show a bubble notification after adding
* Notify the user if they try to favourite a template when they already have the max number of favourites
## Details for QA:
* Check favourites are actually added to user's preferences
## Designs:
https://www.figma.com/design/QWD6oDEz9NMEnF2ppVc4Xq/Template-recall-and-discovery?node-id=765-5322&node-type=canvas&t=yN2wqePQH3we7dMn-0
## Subtasks:
* Add template to favourites on click
* Show bubble notification after saving favourite T377466
* Notify user if they try to favourite a template when they already have the max number of favourites T377460