Adds Shared Channel related API endpoints (#27436)

* Adds Shared Channel management API endpoints

New endpoints for the following routes are added:

- Get Shared Channel Remotes by Remote Cluster at `GET
/api/v4/remotecluster/{remote_id}/sharedchannelremotes`
- Invite Remote Cluster to Channel at `POST
/api/v4/remotecluster/{remote_id}/channels/invite`
- Uninvite Remote Cluster to Channel at `POST
/api/v4/remotecluster/{remote_id}/channels/uninvite`

These endpoints are planned to be used from the system console, and
gated through the `manage_secure_connections` permission.

* Adds i18n messages for API errors

* Fix pagination flaky test

* Fix linter

* Adds the posibility of filtering shared channel remotes by home

---------

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

server/channels/store/sqlstore/shared_channel_store.go

@@ -159,8 +159,10 @@ func (s SqlSharedChannelStore) GetAll(offset, limit int, opts model.SharedChanne
 		return nil, err
 	}
 
-	query := s.getSharedChannelsQuery(opts, false)
-	query = query.OrderBy("sc.ShareDisplayName, sc.ShareName").Limit(safeLimit).Offset(safeOffset)
+	query := s.getSharedChannelsQuery(opts, false).
+		OrderBy("sc.ShareDisplayName, sc.ShareName").
+		Limit(safeLimit).
+		Offset(safeOffset)
 
 	squery, args, err := query.ToSql()
 	if err != nil {
@@ -459,25 +461,49 @@ func (s SqlSharedChannelStore) GetRemoteByIds(channelId string, remoteId string)
 }
 
 // GetRemotes fetches all shared channel remotes associated with channel_id.
-func (s SqlSharedChannelStore) GetRemotes(opts model.SharedChannelRemoteFilterOpts) ([]*model.SharedChannelRemote, error) {
+func (s SqlSharedChannelStore) GetRemotes(offset, limit int, opts model.SharedChannelRemoteFilterOpts) ([]*model.SharedChannelRemote, error) {
+	if opts.ExcludeHome && opts.ExcludeRemote {
+		return nil, errors.New("cannot exclude home and remote shared channel remotes")
+	}
+
+	if offset < 0 {
+		return nil, errors.New("offset must be a positive integer")
+	}
+	if limit < 0 {
+		return nil, errors.New("limit must be a positive integer")
+	}
+
 	remotes := []*model.SharedChannelRemote{}
 
 	query := s.getQueryBuilder().
-		Select(sharedChannelRemoteFields("")...).
-		From("SharedChannelRemotes")
+		Select(sharedChannelRemoteFields("scr")...).
+		From("SharedChannelRemotes scr").
+		OrderBy("scr.Id")
 
 	if opts.ChannelId != "" {
-		query = query.Where(sq.Eq{"ChannelId": opts.ChannelId})
+		query = query.Where(sq.Eq{"scr.ChannelId": opts.ChannelId})
 	}
 
 	if opts.RemoteId != "" {
-		query = query.Where(sq.Eq{"RemoteId": opts.RemoteId})
+		query = query.Where(sq.Eq{"scr.RemoteId": opts.RemoteId})
 	}
 
 	if !opts.InclUnconfirmed {
-		query = query.Where(sq.Eq{"IsInviteConfirmed": true})
+		query = query.Where(sq.Eq{"scr.IsInviteConfirmed": true})
 	}
 
+	if opts.ExcludeHome {
+		query = query.Join("SharedChannels sc ON (scr.ChannelId = sc.ChannelId)").
+			Where(sq.Eq{"sc.Home": false})
+	}
+
+	if opts.ExcludeRemote {
+		query = query.Join("SharedChannels sc ON (scr.ChannelId = sc.ChannelId)").
+			Where(sq.Eq{"sc.Home": true})
+	}
+
+	query = query.Offset(uint64(offset)).Limit(uint64(limit))
+
 	squery, args, err := query.ToSql()
 	if err != nil {
 		return nil, errors.Wrapf(err, "get_shared_channel_remotes_tosql")