MM-60240 Sanitize Channels based on user permissions (#28086)

* initial commit

* add unit tests

* update tests, self review

* update tests to verify something returned.

* update app-layer

* update unit tests

* fix tests

* add check for PermissionSysconsoleReadComplianceDataRetentionPolicy

* revert package-lock

* review suggestions

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

server/public/model/channel.go

@@ -356,6 +356,15 @@ func (o *Channel) GetOtherUserIdForDM(userId string) string {
 	return otherUserId
 }
 
+func (o *Channel) Sanitize() Channel {
+	return Channel{
+		Id:          o.Id,
+		TeamId:      o.TeamId,
+		Type:        o.Type,
+		DisplayName: o.DisplayName,
+	}
+}
+
 func (t ChannelType) MarshalJSON() ([]byte, error) {
 	return json.Marshal(string(t))
 }