Subspace templates: updated create subspace dialog with option to choose template

[SimoneZaza]

Description

As a user, I want to be able to use a subspace template when I create a subspace As a user, I want the design of the create subspace dialog to be consistent with the rest of the platform

Acceptance criteria

Change the Subspace Create dialog to the 'new' style

• [ ] Title (required)
• [ ] Tagline
• [ ] Description
• [ ] Tags
• [ ] Visuals
• [ ] Template
• [ ] Change template button opens library, eg like clicking on the library button in the whiteboard works
• [ ] Tutorials: radio on/off (default = off)
• [ ] Only title is required

Additional Context

Screen shots / UX designs / data that are relevant.

Areas that will be affected

Design: https://www.figma.com/design/eHqxhDSrUZUyTTCmY2L5c5/Subspace-Templates?node-id=125-1563&t=vfIPktD1WUXa7Or8-1 Flow: https://alkem.io/building-alkemio-org/challenges/improvingtheusere-6400/collaboration/subspacetemplates