Add ocis idm resetpassword subcommand

This allows resetting the ocis admin user's password (when ocis is
not running) when running with the builtin LDAP server.

Fixes #4084
This commit is contained in:
Internal Server Error - Gitea: Git with a cup of tea
500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f