make ftp and socks proxies optional

[georgejdli]

(Opening pull requests from master branch to trigger Github actions)

Ran into this issue with 4.13.0.0 when trying to use the firefox driver config:

org.openqa.selenium.SessionNotCreatedException: Could not start a new session. Response code 500. Message: Since Firefox 90 'ftpProxy' is no longer supported

And ran into this on Chrome, Edge, and Firefox driver config where the plugin was not setting the socksVersion in the org.openqa.selenium.Proxy object (default value is null) :

org.openqa.selenium.SessionNotCreatedException: Could not start a new session. Response code 400. Message: invalid argument: entry 0 of 'firstMatch' is invalid
from invalid argument: cannot parse capability: proxy
from invalid argument: 'socksVersion' must be between 0 and 255 

So I dug into the source code and found that there's no way to selectively unset the different protocol proxies to sidestep these issues.

This PR aims to address this issue by allowing the user to unset FTP and SOCKS proxies individually by adding the appropriate check boxes for the user to toggle.

[undera]

Duplicate of #35