Option to limit which transports the server should accept

[FT-JMendyk]

Is your feature request related to a problem? Please describe.
Due to performance reasons, in my system exposing socket.io server, clients are expected to use only the non-polling websocket transport. As such, I would like to stop users from successfully connecting to my system if they attempt to connect using the polling transport.

Describe the solution you'd like
The Javascript and Java Socket.IO libraries provide an option in the Server's constructor to specify transports that will be allowed on the server-side:

• JavaScript: https://socket.io/docs/v4/server-options/#transports
• Java - netty-socketio: https://javadoc.io/static/com.corundumstudio.socketio/netty-socketio/1.7.19/com/corundumstudio/socketio/Configuration.html#setTransports-com.corundumstudio.socketio.Transport...-

I suggest adding an argument for Server's constructor, defining which transports should the server accept.
Should the client connect with a transport outside of the list of accepted ones, the server should respond with an informative error message.

Describe alternatives you've considered
If client is allowed to connect with polling transport, it will cause substantial performance issues, or even lead to (not easily relatable to the cause) exceptions inside python-engineio in specific cases. Thus providing an option to limit supported transports in the server seems like the only solution.

Additional context
As far as I am concerned, implementing this issue might require changes in python-engineio. However, since I am interested in setting allowed transports in socket.io server, I decided to create feature request here.