[TeamMailbox] Refactor webadmin routes on team mailbox member management

[Arsnael]

Refactor webadmin routes on team mailbox member management to take into account the new role field of a member. Reminder that the role of a manager is symbolized by the user getting the right a on the tyeam mailbox.

• Showing roles when listing team mailbox members:

curl -XGET http://ip:port/domains/domain.tld/team-mailboxes/marketting/members

[
  {
     "username": "bob@domain.tld",
     "role": "manager"
  },
  {
     "username": "alice@domain.tld",
     "role": "member"
  },
...
]

• Add new manager or promote existing user with role manager:

curl -XPUT http://ip:port/domains/domain.tld/team-mailboxes/marketing/members/bob@domain.tld?role=manager

• Add new member or unpromote existing manager

curl -XPUT http://ip:port/domains/domain.tld/team-mailboxes/marketing/members/bob@domain.tld?role=member

Absence of the query param role will default to current behavior, adding a user with role member to the team mailbox.

Refactor as well the tests, and the tests should pass with the new model

Dont forget to readapt the webadmin doc in consequence as well

[quantranhong1999]

We need webadmin docs changes too.

[hungphan227]

pr https://github.com/linagora/tmail-backend/pull/1105