Middleware support continues...

[mathieucarbou]

No description provided.

[mathieucarbou]

@hoeken : here are some missing fixes. I can run part of the examples now - but didn't have time to finish testing.

Some notes:

• middleware chain is now lazy and only initialised if used
• added a managed boolean to know if we have the right to delete a middleware. User can implement its own middleware and add it to many chains, so removing an endpoint should not delete a user middleware.
• Lot od ESP_LGOD traces added that we will have to comment out later ;-)

There are still room for memory / perf improvement I saw in the codebase overall, which I will do later.

Another thing to do is to port here the 3 middleware from there: https://github.com/espressif/arduino-esp32/pull/10186/files#diff-3cb168cea5ae30c1231e419a9aa971e09641fae64a1b84bd42428242f875a980

• cors is done
• authentication: do we miss some auth type compares to Arduino WebServer ?
• logging: I added a curl-like logging middleware but we miss some features to be on par with my Arduino PR like getting the HTTP version of the request or server, getting the list of request headers, etc. Also, right now it does not log the response headers, this is something to fix (didn't have time to look further)

[mathieucarbou]

@hoeken : do not forget to merge this PR before adding more stuff in v2... thanks!