Add SSL bundle support to LDAP auto-configuration

[dhruv9b]

Spring Boot's LDAP auto-configuration currently supports LDAPS URLs, but there is no way to associate a named SSL Bundle with the auto-configured LdapContextSource.

This change adds support for configuring an SSL Bundle through spring.ldap.ssl.bundle.

The implementation:

• Adds SSL Bundle configuration to LdapProperties.
• Resolves the configured SslBundle through SslBundles.
• Applies the bundle's SSLSocketFactory to a DefaultTlsDirContextAuthenticationStrategy when no custom authentication strategy is configured.
• Preserves the existing authentication-strategy behavior when custom strategies are present.
• Adds the required Testcontainers connection-details overrides for the new LdapConnectionDetails API.
• Adds tests covering SSL Bundle configuration, custom authentication strategies, multiple strategies, and the resulting SSL socket factory.

This allows applications to use dedicated SSL/TLS configuration for LDAP through Spring Boot's existing SSL Bundle infrastructure without replacing the auto-configured LdapContextSource or relying on JVM-wide SSL properties.

The LDAP module tests pass successfully.