Deprecate `salt.cloud-libcloudfuncs.libcloud_version` unil Salt Helium.

Instead use `salt.cloud-libcloudfuncs.check_libcloud_version`.
`LIBCLOUD_MINIMAL_VERSION` is now defined as a tuple.

Because tuples are comparable.
Update to the tuple based libcloud version requirement.

Double to single quotes and other minor formatting changes.
Libcloud requirement check is now done on the cloud parser class.
The `salt-cloud` script fails with missing or non sufficient libcloud version

Refs #10569.
No need to an additional check, the parser handles it
Late import in order not to break setup.
Merge pull request #10576 from s0undt3ch/hotfix/cloud-libcloud

libcloud check improvements