Subspace templates: management of platform default templates

[techsmyth]

Description

As a support user I want to be able to manage platform default templates

Acceptance criteria

• [ ] TemplatesManager to be a generic component, used on both Space and Platform level
• [ ] Add TemplatesManager to the platform admin area, as another tab at the end?
• [ ] Templates manager component to allow a) managing the set of collaboration templates available at platform level b) selecting the collaboration template to use for a given default template
• [ ] ...

TBD: only show collaboration templates in the associated templatesSet?

Additional Context

Design: https://www.figma.com/design/eHqxhDSrUZUyTTCmY2L5c5/Subspace-Templates?node-id=1-2&t=RqcxSnrvIY04Zszx-1

Areas that will be affected

To be added during the refinement