PCT: Add support of passing plugin version overrides

Currently PCT run just fails when running a Pipeline-dependent test with JDK11. It happens due to the known compat issue in Pipeline:Support plugin. We need to somehow workaround it to enable testing with Java 11

Acceptance criteria:

• It is possible to override a plugin dependency version by passing a parameter to PCT
• It is possible to pass an incrementals version via such parameters
• The change is tested with Pipeline: Support patch for Java 11 and, for example, mailer plugin