modular session management daemon

ecs #24

Merged r0chd.pl
targeting master from ecs
Merged opened by and assigned to r0chd.pl
targeting master from ecs
Commits 31

match session to seat by id instead of name
store device on ecs
store seat and client in ecs
store session in ecs
init world
client id
use SessionId wherever it makes sense
update crates
fix: resolve clippy warnings
get session by uid
readme
add shell completions
rework cli
configurable pam service
delegate cgroup management and fix user/group permissions management
improve finix and nixos vms
tty switching, seat management
XDG_RUNTIME_DIR creation
active session tracking
lock-session unlock-session and improved semantics of terminate/kill
kill-session and terminate-session
rename to sessiond
get session by pid
cgroup handling
rename pam protocol
init finix vm
add moxseatd to nixos-vm
daemon: added leader, timestamp and seat(need registration protocol though)
ctl: init
daemon: introduce info object
daemon: init