treewide: add missing systemd ordering directives

In particular, we were missing `sops-install-secrets.service` in a ton
of places, and `network-online.target` for some homebrewn services.

This has caused failure of some services on machine startup.

hosts/bicep/services/mysql/default.nix

@@ -56,9 +56,13 @@ in
 
   systemd.services.mysql = lib.mkIf cfg.enable {
     after = [
+      "sops-install-secrets.service"
       "systemd-tmpfiles-setup.service"
       "systemd-tmpfiles-resetup.service"
     ];
+    requires = [
+      "sops-install-secrets.service"
+    ];
 
     serviceConfig = {
       BindPaths = [ "${dataDir}:${cfg.dataDir}" ];