Organization create from GUI v2

[touilleMan]

Currently organization creation on Parsec client GUI is done in two times:

• call the saas website (https://my.parsec.cloud/) to register with a email & organization name, the website then call the Parsec backend to create the organization and return to the client the bootstrap token
• bootstrap the organization

This is not great for multiple reasons:

• the saas website is too much coupled with Parsec, this make the Parsec client dependant on an external undocumented API
• the organization creation from the GUI is not possible for an arbitrary backend (only the one provided by the saas website)
• saas website doesn't know when an organization is bootstrapped, this create complex state to manage (typically when a user claim an organization, loose the token before bootstrapping it, then wants the claim again the same organization)

To solve this, we should modify the way we create organization:

• add an option in the backend configuration to accept organization bootstrap without prior organization create
• add a webhook system to call an address when the organization bootstrap is done