Issue #10437 - Simplify jetty-deploy with eye on Environment use

[joakime]

This is a minimal commit version of PR #12583 with an eye on preserving git history via manual move/renames.

Fixes #10437

[joakime]

I have been comparing the HEAD of the two branches with the following technique...

I have 2 git clones.
One clone directory called 12.1.x with checkout of branch fix/12.1.x/unify-deploy
Other clone directory called 12.1.x.alt with checkout of branch fix/12.1.x/deploy-refactor-minimal-commits
Then run the following command line from the parent directory of both.

$ cat diff-exclude.log 
target
*.iml
.idea
.git
*.log
*.versionsBackup
*.orig
*.rej
reports
*.swp
*.patch
*.diff
$ diff -u -r --exclude-from=diff-exclude.log 12.1.x 12.1.x.alt