Flask-shell2http

**Patch release after [v1.4.0](https://github.com/Eshaan7/Flask-Shell2HTTP/releases/tag/v1.4.0).**

Fixed Backward compatibility issues.

**Please use v1.4.3 or greater**

- Bug fixes where multipart requests were failing because of nested form data. Because of this the multipart (file containing) POST request now has an updated schema (examples have been updated accordingly).
- Dropped dataclass for report generation because it causes various bugs in python 3.6.

- One can now define a callback function when registering a command. These can be plain functions or Flask/blinker signals to enable reactive/event-based programming.
- A timeout has been added when invoking commands. This attribute can be passed in the JSON request body. Default value is `3600` seconds.
- Added `returncode` attribute to response JSON.

> Note: Please see [Examples](https://flask-shell2http.readthedocs.io/en/stable/Examples.html) section for the relevant code in such use-cases.

- under-the-hood improvements (decreased the memory footprint of the extension to very low value)
- Added type-hinting in almost all places in the source code.

- added a `result_url` field in the POST request's response.
- Much cleaner log messages than before
- Better memory management by reducing some duplicate class instances.
- under-the-hood small bug fixes.

- Fixed JSON enc error.
- Faster hashing