[cfid-669] Add UsernamePasswordExtractingAuthenticationManager

[#45987701] Login server changes to support vmc and LDAP
Remove vmc headers to prevent duplicates
[cfid-669] Add ldap profile and test case for context

The war now contains all the ldap dependencies and there is a
Spring profile cdalled "ldap" that switches it on for authentication
only. The LDAP query might need to be tweaked and there is a
URL externalized to `ldap.base.url`.

[Fixes #45987701] Login server changes to support vmc and LDAP