Following introducing a new role for announcement subchannels, the first step I'd like to take is to give everyone added to the channel the Voiced role. This is not permanent, and will not be landed as-is, but it's an intermediate step in separating out Members and Voiced.

In changeRole, changeRoleThreadQuery(threadID, role) is called to get the intended role and permissions for the users being added to the thread. Naturally, this is the default_role column in MariaDB. We'll want to do some updates here to ultimately decide whether Voiced or Members is the appropriate role.

In this task, I'll make it so every new member gets Voiced instead of Members, and a later task will update this to check whether the user has 'Voiced in announcement channels' permission, and assign them a role accordingly.

Addresses ENG-5635

Tested this in three ways:

• Confirmed that new users added to the announcement subchannel had voiced permissions in the memberships table in MariaDB
• Confirmed that new users could automatically speak in announcement subchannels (since they have the Voiced role)
• Changed the member pill that shows the role to use the current threadInfo (as opposed to the community thread info) just to see that:
  • in announcement subchannels, new members added had the Voiced role
  • in normal subchannels, new members added had the Members role still