Route refactor and fixes, CPython example

[michalpokusa]

This is a somewhat of a minor change, that does not affect users as it does not change the library's API.
While making on of my projects I noticed that on each request multiple Route objects are created and multiple re methods are called.

This PR changes the way Server handles it's routes. New method is more efficient and has some fixes compared to the current way.

⭐ Added:

• Additinal validation to path in Route constructor
• EDIT1: Example of using adafruit_httpserver with CPython (resolves add cpython example #77)

🗑️ Deleted:

• _Routes class as it is no longer needed

🪛Fixes:

• Literal dots in paths now behave correctly, before they matched every character
• Before ... and .... could be used in other places than between slashes, now the error is raised when trying to do so

🛠️ Updated/Changed:

• Route now has separate path and path_pattern, the later one is created using separate method for better readability
• Route.matches had docs with typos, after the change docs were updated so it is no longer the case
• EDIT1: Server.serve_forever defaults poll_interval to 0.1s and catches KeyboardInterrupts during sleeping, it also sleeps only if no request were processed, so it will not affect performance during bursts

🏗️ Refactor:

• Now it is the Server's responsibility to find a matching Route
• Only method and path is passed when finding a matching Route, this way we are not creating multiple unnecessary Route objects on every request
• Example that shows manual static files handling is now more verbose, which resolves instructions error #75

[FoamyGuy]

This looks good to me. I tested a few examples successfully on a Feather ESP32-S3 TFT.

I also tested the new cpython example successfully.

I had to run it with sudo python in my environment for it to work, I was getting Permission Denied tracing back to socket.bind() without sudo. I'm not sure if that is intentional or if there is some way to lower the permission level needed. But it does make sense to me since it's binding to default port on the host PC to control traffic. Maybe not using 0.0.0.0 IP? (I tried 127.0.0.1 as well but it did not change behavior) or perhaps some port other than 80 could have lower permissions perhaps.

Thank you @michalpokusa and @tedder