Problems: auto-fix & problem panel (#541)

Test cases:
- [x] create-ts-errors
  - [x] with auto-fix
  - [x] without auto-fix 
- [x] create-unfixable-ts-errors
- [x] manually edit file & click recheck
- [x] fix all
- [x] delete and rename case

THINGS
- [x] error handling for checkProblems isn't working as expected
- [x] make sure it works for both default templates (add tests) 
- [x] fix bad animation
- [x] change file context (prompt/files)

IF everything passes in Windows AND defensive try catch... then enable
by default
- [x] enable auto-fix by default

src/ipc/utils/file_utils.ts

@@ -92,3 +92,10 @@ export async function writeMigrationFile(
 
   await fsExtra.writeFile(migrationFilePath, queryContent);
 }
+
+export async function fileExists(filePath: string) {
+  return fsPromises
+    .access(filePath)
+    .then(() => true)
+    .catch(() => false);
+}