test: Added code for creating tests.

feat: Moved diagnostics to visitor instead of listener.
refactor: Cleaned up existing implementations, for (hopefully) easier future implementaitons.

Author: ViTeXFTW

.vscode-test.mjs

@@ -0,0 +1,5 @@
+import { defineConfig } from '@vscode/test-cli';
+
+export default defineConfig({
+	files: 'client/out/test/**/*.test.js',
+});

.vscodeignore

@@ -4,6 +4,7 @@
 .gitignore
 **/tsconfig.json
 **/tsconfig.base.json
+**/*.js.map
 contributing.md
 .travis.yml
 client/node_modules/**