Add BigLDAP topology

[thalman]

This patch expects that ldap container/vm has ldap backup 'largedata'. This backup is restored when BigLDAP topology is used.

Restore process is quite fast (~2s).

[gemini-code-assist]

Code Review

This pull request introduces a new BigLDAPTopologyController and its corresponding topology mark BigLDAP to support LDAP topologies with large amounts of users and groups. The feedback points out several issues in the topology_setup implementation of BigLDAPTopologyController, including bypassing the self.provisioned check, hardcoding service management commands and instance names instead of using existing abstractions, and missing error handling decorators. A refactoring suggestion is provided to address these issues.

[gemini-code-assist]

There are several issues with the current implementation of topology_setup in BigLDAPTopologyController:

1. Bypassing self.provisioned: The setup commands are executed even if self.provisioned is True. This defeats the purpose of pre-provisioned topologies (which are meant to skip setup/provisioning steps to save time).
2. Hardcoded Service Management: Hardcoding systemctl stop dirsrv@localhost.service and systemctl start dirsrv@localhost.service bypasses the LDAPHost service management abstraction (ldap.stop() and ldap.start()), which respects the configured ldap_service_name.
3. Hardcoded Instance Name: Hardcoding slapd-localhost assumes the instance name is always localhost. We can dynamically extract the instance name from ldap._ldap_service_name.
4. Missing Error Handling Decorator: Other topology controllers use @BackupTopologyController.restore_vanilla_on_error to ensure the environment is restored to a clean state if setup fails.

We can address all of these by refactoring the method.

Suggested change

	def topology_setup(self, client: ClientHost, ldap: LDAPHost) -> None:
	ldap.conn.run(
	"systemctl stop dirsrv@localhost.service && "
	"dsctl slapd-localhost bak2db largedata && "
	"systemctl start dirsrv@localhost.service"
	)
	super().topology_setup()
	@BackupTopologyController.restore_vanilla_on_error
	def topology_setup(self, client: ClientHost, ldap: LDAPHost) -> None:
	if not self.provisioned:
	instance = ldap._ldap_service_name.split("@")[-1].split(".")[0]
	ldap.stop()
	ldap.conn.run(f"dsctl {instance} bak2db largedata")
	ldap.start()
	super().topology_setup()