[MM-12476] Consistent paging arguments limit/offset vs page/perPage for plugin API (#9838)

* Change GetTeamMembers() and GetPublicChannelsForTeam() arguments to page, perPage for plugin API

* Add test for GetPublicChannelsForTeam()

* Add test for GetTeamMembers()

* Changes as requested

* Change return from GetPublicChannelsForTeam() to []*model.Channel

app/plugin_api.go

@@ -132,8 +132,8 @@ func (api *PluginAPI) DeleteTeamMember(teamId, userId, requestorId string) *mode
 	return api.app.RemoveUserFromTeam(teamId, userId, requestorId)
 }
 
-func (api *PluginAPI) GetTeamMembers(teamId string, offset, limit int) ([]*model.TeamMember, *model.AppError) {
-	return api.app.GetTeamMembers(teamId, offset, limit)
+func (api *PluginAPI) GetTeamMembers(teamId string, page, perPage int) ([]*model.TeamMember, *model.AppError) {
+	return api.app.GetTeamMembers(teamId, page*perPage, perPage)
 }
 
 func (api *PluginAPI) GetTeamMember(teamId, userId string) (*model.TeamMember, *model.AppError) {
@@ -246,8 +246,9 @@ func (api *PluginAPI) DeleteChannel(channelId string) *model.AppError {
 	return api.app.DeleteChannel(channel, "")
 }
 
-func (api *PluginAPI) GetPublicChannelsForTeam(teamId string, offset, limit int) (*model.ChannelList, *model.AppError) {
-	return api.app.GetPublicChannelsForTeam(teamId, offset, limit)
+func (api *PluginAPI) GetPublicChannelsForTeam(teamId string, page, perPage int) ([]*model.Channel, *model.AppError) {
+	channels, err := api.app.GetPublicChannelsForTeam(teamId, page*perPage, perPage)
+	return *channels, err
 }
 
 func (api *PluginAPI) GetChannel(channelId string) (*model.Channel, *model.AppError) {