These endpoint are similar in many ways, therefore just one commit. Their
functionality is basically same as in lorax except for error messages and
weird edge cases when handling trailing slashes.
closes#64, closes#65
osbuild-composer now uses socket activation instead of hardcoded paths
in the code. osbuild-worker is an http client therefore it uses only
service unit. osbuild-worker must be started after the socket is
created. osbuild-composer service requires osbuild-worker to run, because without
it no jobs can be started.
osbuild-composer is executed as a regular user (newly created
_osbuild-composer user) as opposed to the worker which must run as root
in order to execute osbuild itself
