Test clusters currently has its own set of logic for dealing with
finding different versions of Elasticsearch, downloading them, and
extracting them. This commit converts testclusters to use the
DistributionDownloadPlugin.
* TestClusters: Convert the security plugin
This PR moves security tests to use TestClusters.
The TLS test required support in testclusters itself, so the correct
wait condition is configgured based on the cluster settings.
* PR review
This adds a new security/qa test for TLS on a basic license.
It starts a 2 node cluster with a basic license, and TLS enabled
on both HTTP and Transport, and verifies the license type, x-pack
SSL usage and SSL certificates API.
It also upgrades the cluster to a trial license and performs that
same set of checks (to ensure that clusters with basic license
and TLS enabled can be upgraded to a higher feature license)
Backport of: #40714