Basic Auth to LDAP auth pass-through

[eidottermihi]

Is your feature request related to a problem? Please describe.

Currently, authentication on REST endpoints and authentication for LDAP are two separate mechanisms. From LDAP server point of view this has severe disadvantages, because the authentication provided misses information about the actual applications using the data from LDAP.

Describe the solution you'd like

Add the possibility to pass down Basic Auth credentials from web layer to LDAP context source.

Additional context

https://docs.spring.io/spring-ldap/reference/configuration.html#spring-ldap-custom-principal-credentials-management