Options for apiurls can be set via OSC_HOST_<ALIAS>_<OPTION>=...
This requires a configured alias in the config file.
Setting the default apiurl via OSC_APIURL=... was working already.
Also OSC_CONFIG= / --config= was already implemented to skip loading configuration entirely.
Options for the default apiurl can be now set via:
OSC_USERNAME=...
OSC_CREDENTIALS_MGR_CLASS=...
OSC_PASSWORD=...
This, for example, makes running osc in containers with
credentials stored in environmental variables possible:
OSC_CONFIG= OSC_APIURL=<url> OSC_USERNAME=<user> OSC_PASSWORD=<password> osc ...