feat: add git:from-image support

The new command superscedes the previous tags plugin, and integrates docker image deployment with the general build process.

While `docker image load` is not supported, this otherwise completely handles all previous workflows supported by the `tags:deploy` command, while doing so in a much easier to use interface.

Closes #4296

plugins/git/subcommands/from-image

@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+source "$PLUGIN_AVAILABLE_PATH/git/internal-functions"
+set -eo pipefail
+[[ $DOKKU_TRACE ]] && set -x
+
+cmd-git-from-image "$@"