feat(build)!: add ability to output as directory and/or archive

This changes the filename pattern of the resulting archive, for example:

Old:

    Emacs.app-[master][2021-05-19][6ae3f7e][macOS-11.3][x86_64].tbz
New:

    Emacs.2021-05-19.6ae3f7e.master.macOS-11-3.x86_64.tbz

Emacs.app also resides within a folder in the archive now instead of the
in the root. For the above example, the path to Emacs.app within the
archive would be:

    Emacs.2021-05-19.6ae3f7e.master.macOS-11-3.x86_64/Emacs.app

Archive creation can also be skipped by passing in --no-archive, which
will instead leave a build folder with the same name as the archive.

If you want to keep the build directory, and also a create archive, pass
in --archive-keep-build-dir.

BREAKING CHANGE: New archive naming convention, and folder structure
within archive.

README.md

@@ -81,6 +81,11 @@ Options:
         --no-frame-refocus           Apply no-frame-refocus patch (default: disabled)
         --[no-]github-auth           Make authenticated GitHub API requests if GITHUB_TOKEN environment variable is set.(default: enabled)
         --work-dir DIR               Specify a working directory where tarballs, sources, and builds will be stored and worked with
+    -o, --output DIR                 Output directory for finished builds (default: <work-dir>/builds)
+        --build-name NAME            Override generated build name
+        --dist-include x,y,z         List of extra files to copy from Emacs source into build folder/archive (default: COPYING)
+        --[no-]archive               Enable/disable creating *.tbz archive (default: enabled)
+        --[no-]archive-keep          Enable/disable keeping source folder for archive (default: disabled)
         --plan FILE                  Follow given plan file, instead of using given git ref/sha
 ```