Specification use raw spec on clone (spec-first#1830)

Fixes spec-first#1829.



Changes proposed in this pull request:

 - Use _raw_spec when cloning

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Co-authored-by: Robbe Sneyders <robbe.sneyders@gmail.com>

Set starlette upperbound version to <0.33 (spec-first#1828)

Temporary fix for spec-first#1826

We should release this asap.

Fix CORS headers not set on exceptions (spec-first#1821)

Fixes spec-first#1820.
Correct error handling in response to CORS.


Changes proposed in this pull request:

- Add a MiddlewarePosition before Exception handling so CORS is always
returned
- Add ServerError Middleware to handle unhandled errors between the
ServerError- and ExceptionMiddleware
 - Update corresponding docs

---------

Co-authored-by: Robbe Sneyders <robbe.sneyders@ml6.eu>

Add more detailed v3 migration guide (spec-first#1815)

Fixes spec-first#1794
Fixes spec-first#1802

Fix FlaskApp exception handlers (spec-first#1788)

Fixes spec-first#1787 

In the `FlaskApp`, the error handlers were still registered on the
underlying Flask app instead of on the `ExceptionMiddleware`, which led
to them not following the documented behavior.

The documentation was also incorrect about ignoring error handlers
registered on the flask application. We are only ignoring the default
error handlers registered by Flask itself.

This is a breaking change, however, since this functionality was not
following the documented behavior, and 3.0.0 was only recently released,
I propose to release this as a patch version.

Add 3.0 announcement (spec-first#1774)

Final update for the 3.0 announcement on our docs.

Update cli docs (spec-first#1763)

Contributes towards spec-first#1531

Bugfix/basepath (spec-first#1716)

Working towards spec-first#1709 

I think we're almost there, some tests I did are now working properly.

Would love to get some feedback/ideas on the implementation and the
tests :)

Fix add_middleware enum comparison (spec-first#1698)

Fixes spec-first#1697

Because of a wrong comparison against the position `Enum`, middleware
was not actually being added to the stack via `add_middleware`. This PR
fixes this, adds a warning when the middleware position cannot be found,
and adds a test.

Remove context keyword from security handlers (spec-first#1690)

Follow-up on spec-first#1671 

Since the request context is available globally, we can remove this
complexity from the security handlers ("There should be one-- and
preferably only one --obvious way to do it.")

In addition it seems like there weren't any tests for the context in
security handler functions, and I don't think there's a lot of value in
a test for checking the context in security functions specifically.