Add SSL validation and connection test to LDAP configuration methods

[adambarreiro]

While PR #732 introduced basic support for LDAP in VMware Cloud Foundation Automation, the implemented methods had a few issues:

• If the LDAP used SSL, the certificate was not trusted, hence the LDAP was configured but useless as it would always fail.
• If LDAP host or port is wrong, the LDAP would be configured but useless as it would always fail.

This PR enhances all implemented methods:

• They check connection against provided hostname and port when requesting setting LDAP. When the LDAP settings are being deleted, there's no check, obviously.
• When SSL is requested in the LDAP settings input parameter, and if trustCertificate flag is true, the methods now automatically trust the certificate if needed. Otherwise (trustCertificate=false), the methods will fail.
• If the SSL certificate is trusted, but configuring the LDAP fails, the certificate is automatically deleted.

Additionally, instead of using dummy vCenter as LDAP server, the testing configuration allows to provide a customised LDAP server:

tm:
  ...
  ldap:
    host: my.ldap.server.net
    port: 636
    isSsl: true
    username: admin
    password: StrongPassword
    baseDistinguishedName: OU=demo,DC=foo,DC=bar,DC=test,DC=net
    type: ACTIVE_DIRECTORY

Last, it also adds support of Trusted Certificates for Tenants (TmOrg), which is required for configuring LDAP with SSL on tenants.

[adambarreiro]

As far as I saw, if you change the host in UI, it doesn't re-trigger the certificate trusting popup. I think it should? So not sure if this should be so "smart" or simplify, but not re-trusting cert for changed host would make LDAP useless again.