[Technical] Consolidate the creation of spaces

[ccanos]

Description

As an Alkemio developer I want a clean codebase

Acceptance criteria

• [ ] CreateSpaceDialog and DashboardCreateSpaceDialog should be a single file with common components extracted.
• [ ] Space to be created from the account page of a user / org
• [ ] Remove support for creating a new space via administration

Additional nice-to-have requirements (ui/ux)

• [ ] remove the message from the dialogs: To create a safe environment to train your Virtual Contributor, you first need to create a Space. Choose a plan for this Space below.
• [ ] add '(optional)' behind the tagline and tags e.g. Tagline (optional);
• [ ] add 'Host' label to the host field;

Additional Context

CreateSpaceDialog is used in the new My Account tab, in My Profile section. DashboardCreateSpaceDialog is the first version to create a space dialog that we had in My Dashboard. The problem is it redirects to the space automatically after creation, and relays on urls to work. We want a unified approach, for now we have copy&pasted most of the old one into the new CreateSpaceDialog.

Screen shots / UX designs / data that are relevant.

Areas that will be affected

• My Account Tab under users' profile;
• My Dashboard's create a space flow (/create-space path currently);
• Admin -> Spaces;

Note that the same Create Dialog acts differently on close/complete depending on where it's opened.