refactor(app/Support): Remove JsonFixer class and associated tests

- Delete the JsonFixer class, which was responsible for fixing JSON formatting.
- Remove tests related to invalid JSON datasets and JsonFixer functionality.
- Update PHPUnit configuration to exclude the deleted JsonFixer file.
- Streamline the codebase by eliminating unnecessary complexity from the JSON handling process.

Author: ityaozm@gmail.com

app/Support/JsonFixer.php

@@ -22,7 +22,6 @@
     </include>
     <exclude>
       <!--<directory>app/Contracts</directory>-->
-      <file>app/Support/JsonFixer.php</file>
       <file>app/Support/helpers.php</file>
       <file>app/Mixins/StrMacro.php</file>
     </exclude>