Add DELETE method to ensure POST request rollback

[operatr]

If setUnicodePwd or enableAccount fails after the user has already been added to LDAP (line 27), the function returns an error but leaves the partially created user in LDAP without proper cleanup. This could result in disabled/unusable user accounts accumulating in Active Directory.

Consider implementing a rollback mechanism to delete the user entry if password setting or account enabling fails, or at minimum document this behavior and its implications.

			}
			// Attempt to delete the user to rollback
			delReq := ldap.NewDelRequest(dn, nil)
			if delErr := conn.Del(delReq); delErr != nil {
				if c.logger != nil {
					c.logger.Error("rollback: failed to delete user after setUnicodePwd failure", zap.Error(delErr), zap.String("dn", dn), zap.String("username", u.Username))
				}
			}
			return err
		}
		if err := c.enableAccount(conn, dn); err != nil {
			if c.logger != nil {
				c.logger.Warn("enable account failed", zap.Error(err), zap.String("dn", dn), zap.String("username", u.Username))
			}
			// Attempt to delete the user to rollback
			delReq := ldap.NewDelRequest(dn, nil)
			if delErr := conn.Del(delReq); delErr != nil {
				if c.logger != nil {
					c.logger.Error("rollback: failed to delete user after enableAccount failure", zap.Error(delErr), zap.String("dn", dn), zap.String("username", u.Username))
				}
			}

Originally posted by @Copilot in #1 (comment)