Refactor imports and secrets. Add per system properties and role based secret access.

Highlights
- No need to update flake for every machine anymore, just add a properties.nix file.
- Roles are automatically generated from all machine configurations.
- Roles and their secrets automatically are grouped and show up in agenix secrets.nix
- Machines and their service configs may now query the properties of all machines.
- Machine configuration and secrets are now competely isolated into each machine's directory.
- Safety checks to ensure no mixing of luks unlocking secrets and hosts with primary ones.
- SSH pubkeys no longer centrally stored but instead per machine where the private key lies for better cleanup.

secrets/hostapd-pw-CXNK00BF9176.age

@@ -1,16 +1,9 @@
 age-encryption.org/v1
--> ssh-ed25519 VyYH/Q 3383IYDpr6jhePY89sI7RO5KY6i5Wr/Miy4Tx1IeZEI
-Z4nN390wcZiDQCEJvTBD+v5LetZpjdcVhF8uYIUSkNA
--> ssh-ed25519 xoAm7w vO5L5G+aDSXJvD5MLKHtdfo3Ypd//vl7uO644j0S+ig
-LRIiQOSb4M9FItfqci10ELYgzkCXhOBaWv8iz2He6zA
--> ssh-ed25519 mbw8xA RxxUEOVUfKZyUM7KkUjMm9Z+Ts/et15dMxJm4XVKbzg
-hKS82nZ2v88jqxGW1xprsPk67Czn+PLTxIuOrlgXkpw
--> ssh-ed25519 2a2Yhw FRSIexkNO39x9h4wLVKscOmBIE5I/rOlNGfX+MdUfGo
-1OcV1pJ+/M3wtPnRMDxgcpnsyeFYBqBe5Gbj55dJiCY
--> ssh-ed25519 dMQYog lqtpfP3zAArnAF2M9MtUBhFymnG2S15X88YcW949PTI
-2po8qHUuVbMIzrZ+q746cb9BQ06emGowJJcIGHdHeH8
--> aH,?XIq9-grease ]Y I]hNq dZyR2f@@ Xl"1A`
-U/BZHrNalVSmBUEekZbQ1w95VrFtkskMOuI5lm9thRe2bvTe7Rue382uf0fcfvSE
-Jq7+f/b257KiFaUg8Is1WNNMY55Rw0wrnv9yIBMESxCWmgo
---- rUwKbA9SH9XIRdEXLhDIRj+mEu7BV4w7EwkAd4wZPGI
-ř@±ľ·¦ţµÉćS*ÚŘŔi(˙jW˛(WĆŇ-–€yFůů™ Î<7F><C38E>9 
+-> ssh-ed25519 VyYH/Q X+fXLJz227KkBLu45rb9mUkkIpENSMtZeEJjl6qj5Xw
+AFAFnvsiogoMMwsAJO0DDoaizL9lmCLsF4QHDjmubr0
+-> ssh-ed25519 dMQYog P84+7TBcMFSALTn6FR/aXyqFE9DfOzp38ImkdWj7nE0
+PqOn1OL9Zt0x1pBIYOSKkkS//mbk1OX5pnDGp+OLYeI
+-> @?-grease
+3JvpmcTxdTgvv6vPL8dXEwjR+g
+--- aMYF1SbC+p01YWmg24+Ih78VPQcwzGU/P1cEfgRvXV8
+Ÿ	@$™sžQ¼z<15><>®xkÊNfÛuÕ;§¿ ÎvI0•ªÇÎ^4.?, 8…çî