feature(maven): Apply a set of rules to help with JDK8 upgrade

[gounthar]

Whenever we have to upgrade an outdated plugin, we face the problem a recent maven can't use JDK7, so we're stuck with a plugin we can't update.
I tried jenkins-infra#277 a few manual steps that helped me update a very outdated plugin, mostly by manipulating the existing pom.xml.

Could we use a pom parsing tool to remove offending properties, add parent pom, update Jenkins' minimal version, and so on?

We already made an attempt in #21, but the add-pom-modifier branch is not compatible anymore with upstream/main.

We should try to fill in the voids (some TODO in the code), cherry-picking code whenever it's possible from the add-pom-modifier branch in order to allow a plugin pom using a JDK version older than 8 to be transformed so we can apply standard recipes afterward.