MM-21626, MM-21627 - Plugin API/Hooks Prometheus instrumentati… (#13825)

* MM-21626,MM-21627 - Plugin API/Hooks Prometheus instrumentation

* Updated einterface mocks

* Fixed supervisor tests

* ignoring golint errors for plugin metrics wrappers

* Making golangci happy

* Using variadic form when generating wrapper code

* Removed artificial delay

* Removed comments from tests

* Renaming plugin wrappers to api/hooks_timer_layer

* updating vendor dir and mod files

* Recording plugin api/hook responses in prometheus

* Updated einterfaces-mocks

* Updating go sum

* Updating go sum

* Fixing conflicts

* More conflicts fixing

Co-authored-by: mattermod <mattermod@users.noreply.github.com>

einterfaces/metrics.go

@@ -48,4 +48,9 @@ type MetricsInterface interface {
 	IncrementPostIndexCounter()
 	IncrementUserIndexCounter()
 	IncrementChannelIndexCounter()
+
+	ObservePluginHookDuration(pluginID, hookName string, success bool, elapsed float64)
+	ObservePluginMultiHookIterationDuration(pluginID string, elapsed float64)
+	ObservePluginMultiHookDuration(elapsed float64)
+	ObservePluginApiDuration(pluginID, apiName string, success bool, elapsed float64)
 }