Issue description

As an admin on a portfolio,
When I delete a user from my organization, I want them to be removed from any domains in my organization
so that I know they no longer have any kind of access to my orgs data

Likewise,

As an analyst,
when i delete someone from a portfolio in admin, I want them to be removed from any domains
so that I don't have to open up additional tables to remove them.

Acceptance criteria

• When someone is removed from a portfolio they are removed from the portfolio domains they manage (or are "invited" to manage)
  • keep the new practice of canceling the invitations, don't delete them
  • remove user domain roles for domains in this portfolio
• the above applies to someone removed from a portfolio via django admin portfolio invitations or user portfolio roles AND from the Members table in the registrar view
• remove the user from the org_model_user group if they do not have any portfolios assigned to them anymore <- EDIT 01/23, this AC is obsolete cc @abroddrick
• EDIT 01/23 - new AC - no action needed if deleting a retrieved portfolio invitation. Slack thread here.

Additional context

removing the user from the org model user group is so that they no longer have the waffle flags turned on for them
you should double check ag/staging or stable to be sure of the spelling of this user groups name.

Links to other issues

No response