fix(shortcut): job shortcut only run when have job

The shortcut was always allowed to run, meaning when the player doesn't
have a job, they were sent to the job screen with no job and lost the
view context/sidebar.

- Add utility method to check if the player 'hasJob', being at least 1
job.
- Check if player has job when the key combination is pressed

Resolves danielyxie/bitburner#2013

src/PersonObjects/Player/PlayerObject.ts

@@ -247,6 +247,7 @@ export class PlayerObject implements IPlayer {
   getIntelligenceBonus: (weight: number) => number;
   getCasinoWinnings: () => number;
   quitJob: (company: string) => void;
+  hasJob: () => boolean;
   process: (router: IRouter, numCycles?: number) => void;
   createHacknetServer: () => HacknetServer;
   startCreateProgramWork: (router: IRouter, programName: string, time: number, reqLevel: number) => void;
@@ -531,6 +532,7 @@ export class PlayerObject implements IPlayer {
     this.applyForJob = generalMethods.applyForJob;
     this.getNextCompanyPosition = generalMethods.getNextCompanyPosition;
     this.quitJob = generalMethods.quitJob;
+    this.hasJob = generalMethods.hasJob;
     this.applyForSoftwareJob = generalMethods.applyForSoftwareJob;
     this.applyForSoftwareConsultantJob = generalMethods.applyForSoftwareConsultantJob;
     this.applyForItJob = generalMethods.applyForItJob;

src/PersonObjects/Player/PlayerObjectGeneralMethods.tsx

@@ -1782,6 +1782,15 @@ export function quitJob(this: IPlayer, company: string): void {
   delete this.jobs[company];
 }
 
+/**
+ * Method to see if the player has at least one job assigned to them
+ * @param this The player instance
+ * @returns Whether the user has at least one job
+ */
+export function hasJob(this: IPlayer): boolean {
+  return Boolean(Object.keys(this.jobs).length);
+}
+
 export function applyForSoftwareJob(this: IPlayer, sing = false): boolean {
   return this.applyForJob(CompanyPositions[posNames.SoftwareCompanyPositions[0]], sing);
 }