Fixed #22058 -- Refactored handlers and added a generic mechanism to deal with client and server errors.

**What is done**:

- Refactored handlers into generic ones.
- Deprecated original default views.
- Added generic views.

**Improvements Required**:
- Docs build have several warnings due to removing original handlers.
- A writeup for new views.

**Suggestions**:
- We could add two generic exceptions also: `HttpClientException` and `HttpServerException` to add onto the functionality.

I have created resolve4xx and resolve5xx so as to keep the behaviour as earlier as their was `resolve404/403/400/500` all of which called `_resolve_special`. Basically I think it was for better usage by user as you may see in the tests.