Ministry: Users: Users table user type and role enhancement

As a _Ministry user_, _I want_ to assign the right role to the person _so that_ I make sure that they have proper access to their institution account.

When I look at the table it's confusing when I assigned a role as Admin or User, they show up on the left under User Type and the content above states they are a role.

**Additional Context**
- Roles: Admin, User, Legal Signing Authority, Read only
- Person can have Admin role and Legal Signing Authority role so they would stack on top of each other in alphabetical order in the Role column

**Acceptance Criteria**
- [ ] All roles to be added under the "Role" column
- [ ] Remover "User Type" column [TBD]
- [ ] Content: Update "Admin" tooltip to remove designations [Admin only user type cannot do designations]
- [ ] If user is an admin with Legal Signing Authority and wants to change to another admin, when "Legal Signing Authority" is deselected, provide a list of "Admin" to choose from
- [ ] Validation: If no "Admin" is selected the following content is displayed

> Please select another admin to have the legal signing authority role.

Start from the Ministry users table and the role-assignment flow described in the issue, then trace how User Type, Role, tooltips, and Legal Signing Authority selection are rendered and validated. Confirm the column, tooltip, stacked-role, replacement-admin, and missing-admin validation criteria before considering the work done.

Written by the indexing model from the issue text.