MM-13893: refactor config (#10230)

* refactor utils/config* to config/

* pull validateLdapFilter into app

* clean up Config/GetConfig/GetSanitizedConfig usage

Eliminate app.GetConfig() in favour of just using app.Config() directly,
but expose app.GetSanitizedConfig() for when the old behaviour was
required.

* web: isolate config setup

* TestInvitePeopleProvider: make config explicit

* regenerateClientConfig: avoid racey map access

* integrate watch flag into app.ConfigFile option

* make app.Option return an error

* release.mk: only cp static files from config/

* release.mk: fix cp static files from config/

* api4: TestPlugin cleanup

* s/c/cfg/ for clarity

* fix merge conflict

* testlib: allow customization of testlib driver name

api4/plugin_test.go

@@ -20,19 +20,9 @@ func TestPlugin(t *testing.T) {
 	th := Setup().InitBasic()
 	defer th.TearDown()
 
-	enablePlugins := *th.App.Config().PluginSettings.Enable
-	enableUploadPlugins := *th.App.Config().PluginSettings.EnableUploads
 	statesJson, _ := json.Marshal(th.App.Config().PluginSettings.PluginStates)
 	states := map[string]*model.PluginState{}
 	json.Unmarshal(statesJson, &states)
-	defer func() {
-		th.App.UpdateConfig(func(cfg *model.Config) {
-			*cfg.PluginSettings.Enable = enablePlugins
-			*cfg.PluginSettings.EnableUploads = enableUploadPlugins
-			cfg.PluginSettings.PluginStates = states
-		})
-		th.App.SaveConfig(th.App.Config(), false)
-	}()
 	th.App.UpdateConfig(func(cfg *model.Config) {
 		*cfg.PluginSettings.Enable = true
 		*cfg.PluginSettings.EnableUploads = true