Add delete space/subspace

[EmiliaPavlova]

Added Delete Space block, available under Space settings > settings.

• In Space
• In Subspace
• In Subsubspace: added empty settings with the delete button The Delete button should be available to space admins (and the creator). Confirmation dialog to be presented to the user. After deletion the user is navigated to My Dashboard for Spaces and Subspace Dashboard for sub~ and subsubspaced (not discussed).