feat(systemd-manager): Support sudo password and root detection in SystemdManager; add user/group support in services and templates; add tests and expand README

ts/smartdaemon.classes.service.ts

@@ -8,6 +8,8 @@ export interface ISmartDaemonServiceConstructorOptions {
   command: string;
   workingDir: string;
   version: string;
+  user?: string;
+  group?: string;
 }
 
 /**
@@ -33,6 +35,8 @@ export class SmartDaemonService implements ISmartDaemonServiceConstructorOptions
   public command: string;
   public workingDir: string;
   public description: string;
+  public user?: string;
+  public group?: string;
 
   public smartdaemonRef: SmartDaemon;