Can't set SSL verification to value ssl.CERT_NONE

It seems that it's not possible to either set verify=ssl.CERT_NONE or IntEnum value 0 for requests.

${response}= request.HEAD ${url} verify=0

Test                                             | FAIL |
OSError: Could not find a suitable TLS CA certificate bundle, invalid path: 0

${response}= request.HEAD ${url} verify=ssl.CERT_NONE

Test                                             | FAIL |
OSError: Could not find a suitable TLS CA certificate bundle, invalid path: ssl.CERT_NONE

It would be good to have support for this, as verify=False is still trying to read some SSL response from server end.
There are cases where the server we are sending https requests to has something misconfigured and this is leading to a SSLError.

An example SSLError with verify=False
Caused by SSLError(SSLEOFError(8, '[SSL: UNEXPECTED_EOF_WHILE_READING] EOF occurred in violation of protocol (_ssl.c:1007)'))

This can be bypassed by setting a value of ssl.CERT_NONE to verify argument in python (https://docs.python.org/3/library/ssl.html#ssl.CERT_NONE), so it would be great to have support for this also in robotframework-requests.

Start at the request.HEAD keyword and its verify argument handling in robotframework-requests. Reproduce the reported examples with verify=0 and verify=ssl.CERT_NONE, then confirm that the supported behavior matches Python's SSL constants and the request completes without the invalid-path error.