Is your feature request related to a problem? Please describe.

Part of #7864

Describe the solution you'd like

As a user I wanna be to create email snippets and share them with user groups

• Make it possible to add/edit/delete snippets
• Make it possible to insert snippets
• Make it possible to share snippets
• Documentation feat(user-manual): Add docs for text blocks documentation#12931

Describe alternatives you've considered

No response

Additional context

No response