Add controller sub-terms to the glossary

[oleg-nenashev]

There is a pending terminology discussion in https://groups.google.com/g/jenkinsci-dev/c/x5vdlJDvntw . Once we finalize the decisions, https://www.jenkins.io/doc/book/glossary/ needs to be updated to list the new terms.

[Abhishekverma2002]

Is the issue still Open ?

[zbynek]

Yes, only Controller is mentioned but there should be also some information about Built-in Node (see the linked mailing list discussion for more info about the distinction).