Ldap UserPasswordCredentialLoaderBuilder shouldn't be added by default

As a developer, I would like to connect to RHDS.

During my investigation, I found that while connecting to RHDS, we shouldn't add UserPasswordCredentialLoaderBuilder

In this case, instead of creating a bool property, I decided to set LdapUserPasswordMapperConfiguration.FROM as null by default. When it has a value, then there is an opportunity to set also the VERIFIABLE attribute value. Adding the UserPasswordCredentialLoader and when VERIFIABLE is true are different things.

org.wildfly.security.auth.realm.ldap.LdapSecurityRealmBuilder

        public LdapSecurityRealmBuilder build() {
            assertNotBuilt();
            built = true;

            UserPasswordCredentialLoader upcl = new UserPasswordCredentialLoader(userPasswordAttribute);
            LdapSecurityRealmBuilder.this.addCredentialLoader(upcl);
            if (enablePersistence) LdapSecurityRealmBuilder.this.addCredentialPersister(upcl);
            if (enableVerification) LdapSecurityRealmBuilder.this.addEvidenceVerifier(upcl.toEvidenceVerifier());