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

app/plugin_api.go

@@ -77,7 +77,7 @@ func (api *PluginAPI) GetSession(sessionId string) (*model.Session, *model.AppEr
 }
 
 func (api *PluginAPI) GetConfig() *model.Config {
-	return api.app.GetConfig()
+	return api.app.GetSanitizedConfig()
 }
 
 func (api *PluginAPI) SaveConfig(config *model.Config) *model.AppError {
@@ -85,7 +85,7 @@ func (api *PluginAPI) SaveConfig(config *model.Config) *model.AppError {
 }
 
 func (api *PluginAPI) GetPluginConfig() map[string]interface{} {
-	cfg := api.app.GetConfig()
+	cfg := api.app.GetSanitizedConfig()
 	if pluginConfig, isOk := cfg.PluginSettings.Plugins[api.manifest.Id]; isOk {
 		return pluginConfig
 	}
@@ -93,7 +93,7 @@ func (api *PluginAPI) GetPluginConfig() map[string]interface{} {
 }
 
 func (api *PluginAPI) SavePluginConfig(pluginConfig map[string]interface{}) *model.AppError {
-	cfg := api.app.GetConfig()
+	cfg := api.app.GetSanitizedConfig()
 	cfg.PluginSettings.Plugins[api.manifest.Id] = pluginConfig
 	return api.app.SaveConfig(cfg, true)
 }