Allow caching and checking of shadow entries (passwords)
Cache and serve system id's
improve some security warnings
prepare for multi-resolver
Allow the kanidm provider to be not configured
Allow group extension
* fix typos and misspellings
* use proper capitalization
* Apply suggestions from code review
---------
Co-authored-by: James Hodgkinson <james@terminaloutcomes.com>
The kanidm-unixd-tasks service refuses to start before kanidm-unixd:
```
systemd[1]: Started Kanidm Local Tasks.
(xd_tasks)[29469]: kanidm-unixd-tasks.service: Failed to set up mount namespacing: /run/systemd/unit-root/run/kanidm-unixd: No such file or directory
(xd_tasks)[29469]: kanidm-unixd-tasks.service: Failed at step NAMESPACE spawning /usr/sbin/kanidm_unixd_tasks: No such file or directory
systemd[1]: kanidm-unixd-tasks.service: Main process exited, code=exited, status=226/NAMESPACE
systemd[1]: kanidm-unixd-tasks.service: Failed with result 'exit-code'.
```
Resolve this by ensuring kanidm-unixd gets activated as a dependency.
The ordering ("After") is already in place.
Signed-off-by: Georg Pfuetzenreuter <mail@georg-pfuetzenreuter.net>
