Make password and user name requirements configurable

Summary

Fix caosdb/customers/leibniz-zmt/management#95 Implement caosdb/customers/leibniz-zmt/management#94

See also: #121 (closed)

Focus

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Test Environment

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CHANGELOG.md

@@ -41,6 +41,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+* [caosdb-server#142](https://gitlab.com/caosdb/caosdb-server/-/issues/142)
+  Can't create users with dots in their user names
 * `ldap_authentication.sh <username>` failed on every attempt when used in
   combination with OpenLDAP with default configuration.
 * `ldap_authentication.sh` allowed empty and even wrong passwords when used in