Do some more refactoring

frontend/src/scripts/input/commands/primary-action.ts

@@ -0,0 +1,12 @@
+import { vec2 } from 'gl-matrix';
+import { Command } from '../../commands/command';
+
+export class PrimaryActionCommand extends Command {
+  public constructor(public readonly position?: vec2) {
+    super();
+  }
+
+  public get type(): string {
+    return 'PrimaryActionCommand';
+  }
+}