Fix #1863: Add getHashUpgrades hacknet function

Adds a new functions ofr hacknet servers that returns the list of
available hash upgrades.

src/NetscriptFunctions/Hacknet.ts

@@ -16,6 +16,8 @@ import {
 } from "../Hacknet/HacknetHelpers";
 import { HacknetServer } from "../Hacknet/HacknetServer";
 import { HacknetNode } from "../Hacknet/HacknetNode";
+import { HashUpgrades } from "../Hacknet/HashUpgrades";
+import { HashUpgrade } from "../Hacknet/HashUpgrade";
 import { GetServer } from "../Server/AllServers";
 
 import { Hacknet as IHacknet, NodeStats } from "../ScriptEditor/NetscriptDefinitions";
@@ -166,6 +168,12 @@ export function NetscriptHacknet(player: IPlayer, workerScript: WorkerScript, he
       }
       return purchaseHashUpgrade(player, upgName, upgTarget);
     },
+    getHashUpgrades: function(): string[] {
+      if (!hasHacknetServers(player)) {
+        return [];
+      }
+      return Object.values(HashUpgrades).map((upgrade: HashUpgrade) => upgrade.name);
+    },
     getHashUpgradeLevel: function (upgName: any): number {
       const level = player.hashManager.upgrades[upgName];
       if (level === undefined) {

src/ScriptEditor/NetscriptDefinitions.d.ts

@@ -2290,6 +2290,22 @@ export interface Hacknet {
    */
   spendHashes(upgName: string, upgTarget?: string): boolean;
 
+  /**
+   * Get the list of hash upgrades
+   * @remarks
+   * RAM cost: 0 GB
+   *
+   * This function is only applicable for Hacknet Servers (the upgraded version of a Hacknet Node).
+   *
+   * Returns the list of all available hash upgrades that can be used in the spendHashes function.
+   * @example
+   * ```ts
+   * const upgrades = hacknet.getHashUpgrades(); // ["Sell for Money","Sell for Corporation Funds",...]
+   * ```
+   * @returns An array containing the available upgrades
+   */
+  getHashUpgrades(): string[];
+
   /**
    * Get the level of a hash upgrade.
    * @remarks