Move stubs from ./stubs to ./shared/Stubs

Gathers all shared test code in single place.

tests/unit/shared/Stubs/FunctionParameterStub.ts

@@ -0,0 +1,17 @@
+import { IFunctionParameter } from '@/application/Parser/Script/Compiler/Function/Parameter/IFunctionParameter';
+
+export class FunctionParameterStub implements IFunctionParameter {
+  public name = 'function-parameter-stub';
+
+  public isOptional = true;
+
+  public withName(name: string) {
+    this.name = name;
+    return this;
+  }
+
+  public withOptionality(isOptional: boolean) {
+    this.isOptional = isOptional;
+    return this;
+  }
+}