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

build/release.mk

@@ -32,7 +32,10 @@ package:
 	mkdir -p $(DIST_PATH)/prepackaged_plugins
 
 	@# Resource directories
-	cp -RL config $(DIST_PATH)
+	mkdir -p $(DIST_PATH)/config
+	cp -L config/README.md $(DIST_PATH)/config
+	cp -L config/config.json $(DIST_PATH)/config
+	cp -L config/timezones.json $(DIST_PATH)/config
 	cp -RL fonts $(DIST_PATH)
 	cp -RL templates $(DIST_PATH)
 	cp -RL i18n $(DIST_PATH)