Add to TP build a check that produced TP can be installed in target Eclipse version

Recently, a change in TP (jetty 9.3.6) was introduced and everything built fine with it; until the very end of the build process: during install-tests.
This issue would probably have occured if trying to install all content of the TP into the target Eclipse IDE (using install-grinder or p2director or whatever installation). So it would be good to have inside the TP build (as a "verify" plugin in pom.xml) something that would try to find whether target Eclipse version and our TP are already compatible.

Technical notes:

• Trying to install all IUs from the release train site + our TP seems easier to implement
• We do not need to actually install the artifacts, just making the p2 request and getting whether the request managed to find a working plan without remediation seems enough.