LPS-43045 LR doesn't export a temporary user password to a LDAP-server

Liferay does not send user password to LDAP during user's self-registration process.
There are two use cases:
  - Autogenerated password
  - User's custom password (login.create.account.allow.custom.password=true)

At both cases the password is not propagated to LDAP at beginning because "unencrypted password" is not stored at database and it is not propagated inside User object.

We will use "ServiceContext" object to avoid the problem.