At this point in the T377978 story, it is possible to favourite a template when searching for it in the initial template-search form. This task is to also add a fabourite button to the template editing form that is used both just after selecting a new template and also when clicking the edit button on a template that's already in a wiki page.
This task is only for aadding this to VE; see T385846 for the equivalent for adding to TemplateWizard.
The design is at https://www.figma.com/design/QWD6oDEz9NMEnF2ppVc4Xq/Template-recall-and-discovery?node-id=765-7127&t=zZvtDAHJ3iCCcutY-4
