[Gekidou] Update database to hold if a user is a team or channel admin (#6351)

* Update database to hold if a user is a team or channel admin

* TeamMembership identifier

* Fix handleTeamMembership test

* Update server.md

Co-authored-by: Avinash Lingaloo <avinashlng1080@gmail.com>

docs/database/server/server.md

@@ -55,6 +55,7 @@ ChannelMembership
 id PK string # composition ID Channel.id-User.id
 channel_id string INDEX FK >- Channel.id
 user_id string INDEX FK >- User.id
+scheme_admin bool
 
 CustomEmoji
 -
@@ -241,6 +242,7 @@ TeamMembership
 id PK string # auto-generated
 team_id string INDEX FK >- Team.id
 user_id string INDEX FK >- User.id
+scheme_admin bool
 
 
 TeamSearchHistory