Support for ldap secret engine

[drewmullen]

Closes: #745

Added support for ldap secret engine. both dynamic and static roles are supported. After running the tests locally against a working LDAP i have disabled them because its causing CI to fail. LMK how you want to proceed regarding testing

For testing:

• included unit tests
• integration tests. I enabled them then manually setup connectivity to a local openldap, then i ran the integration tests and they worked great. Below are the dynamic roles created from the unit tests

ldapsearch -x -H ldap://localhost:389 -b "ou=users,dc=example,dc=com" -D "cn=admin,dc=example,dc=com" -w admin "(cn=dynamic-role_*)" cn
...
# dynamic-role_luRsOyQMH3, users, example.com
dn: cn=dynamic-role_luRsOyQMH3,ou=users,dc=example,dc=com
cn: dynamic-role_luRsOyQMH3

# dynamic-role_YtrbBxSbsd, users, example.com
dn: cn=dynamic-role_YtrbBxSbsd,ou=users,dc=example,dc=com
cn: dynamic-role_YtrbBxSbsd

$ ./mvnw test -pl spring-cloud-vault-config-ldap -Dtest=LdapSecretIntegrationTests
...
[INFO] -------------------------------------------------------
[INFO]  T E S T S
[INFO] -------------------------------------------------------
[INFO] Running org.springframework.cloud.vault.config.ldap.LdapSecretIntegrationTests
[INFO] Tests run: 2, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.355 s -- in org.springframework.cloud.vault.config.ldap.LdapSecretIntegrationTests
[INFO] 
[INFO] Results:
[INFO] 
[INFO] Tests run: 2, Failures: 0, Errors: 0, Skipped: 0
[INFO] 
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  2.033 s
[INFO] Finished at: 2025-12-19T16:28:21-05:00
[INFO] ------------------------------------------------------------------------