MM-14897: Changes to be able to add and remove groups from channels. (#10794)

* MM-15162: Changes for LDAP groups removals phase.

* MM-14897: Changes to be able to add and remove groups from channels.

* Update model/client4.go

* MM-14897: PR-requested change to string interpolation.

app/group.go

@@ -165,12 +165,20 @@ func (a *App) ChannelMembersToRemove() ([]*model.ChannelMember, *model.AppError)
 	return result.Data.([]*model.ChannelMember), nil
 }
 
-func (a *App) GetGroupsByChannel(channelId string, page, perPage int) ([]*model.Group, *model.AppError) {
-	result := <-a.Srv.Store.Group().GetGroupsByChannel(channelId, page, perPage)
+func (a *App) GetGroupsByChannel(channelId string, opts model.GroupSearchOpts) ([]*model.Group, int, *model.AppError) {
+	result := <-a.Srv.Store.Group().GetGroupsByChannel(channelId, opts)
 	if result.Err != nil {
-		return nil, result.Err
+		return nil, 0, result.Err
 	}
-	return result.Data.([]*model.Group), nil
+	groups := result.Data.([]*model.Group)
+
+	result = <-a.Srv.Store.Group().CountGroupsByChannel(channelId, opts)
+	if result.Err != nil {
+		return nil, 0, result.Err
+	}
+	count := result.Data.(int64)
+
+	return groups, int(count), nil
 }
 
 func (a *App) GetGroupsByTeam(teamId string, opts model.GroupSearchOpts) ([]*model.Group, int, *model.AppError) {