ipatests: Allow using FQDN with trailing dot as final hostname

When creating a BaseHost instance, the machine's hostname was
reconfigured to have the same shortname prepended the domain name
of the domain where it was defined.

However, it makes sense in certain use cases to define hosts
that have hostnames other than belonging directly in the domain
they were defined in.

Treat input hostnames with trailing dots as static FQDNs that
will not be changed by the name of the domain they were defined in.
ipatests: Fix incorrect UID/GID reference for subdomain users and groups

In legacy client integration test, the test cases that query information
from subdomain about subdomain users and group expected subdomain
users and groups to have the UIDs/GIDs as users and groups in the root
domain.
ipatests: Add Sudo integration test