Remove http_proxy_ args from the client module utils

[mikemorency]

The http_proxy_* args should be removed from the client module utils files. These args do not align with their corresponding parameters (proxy_host, proxy_port), which is confusing.

Since these utils are public, the change must be done as part of a major release

See #261

[mariolenz]

FYI ansible-collections/community.vmware#2503 should make sure community.vmware doesn't break when you remove the http_proxy_* args from the client module utils files in 3.0.0.