feat: improve the LDAP implementation (#615)

* feat(logging): add PV_LOG_LEVEL environment variable to set backend log level

* feat(ldap): Adding a more verbose logging output to debug LDAP issues

* fix(ldap): fixed user logins with special characters within the users dn by switching to ldapts

* feat(ldap): made the member of and email attribute names configurable

* fix(ldap): properly handle email like usernames and fixing #601

* Revert "fix: disable email login if ldap is enabled"

This reverts commit d9cfe697d6.

* feat(ldap): disable the ability for a user to change his email when it's a LDAP user

* feat(ldap): relaxed username pattern by allowing the @ character in usernames

backend/src/constants.ts

@@ -1,3 +1,5 @@
+import { LogLevel } from "@nestjs/common";
+
 export const DATA_DIRECTORY = process.env.DATA_DIRECTORY || "./data";
 export const SHARE_DIRECTORY = `${DATA_DIRECTORY}/uploads/shares`;
 export const DATABASE_URL =
@@ -7,3 +9,7 @@ export const CLAMAV_HOST =
   process.env.CLAMAV_HOST ||
   (process.env.NODE_ENV == "docker" ? "clamav" : "127.0.0.1");
 export const CLAMAV_PORT = parseInt(process.env.CLAMAV_PORT) || 3310;
+
+export const LOG_LEVEL_AVAILABLE: LogLevel[] = ['verbose', 'debug', 'log', 'warn', 'error', 'fatal'];
+export const LOG_LEVEL_DEFAULT: LogLevel = process.env.NODE_ENV === 'development' ? "verbose" : "log";
+export const LOG_LEVEL_ENV = `${process.env.PV_LOG_LEVEL || ""}`;