resolves https://github.com/elastic/kibana/issues/92949
This PR adds two new Kibana config keys to further customize when the proxy
is used when making HTTP requests. Prior to this PR, if a proxy was set
via the `xpack.actions.proxyUrl` config key, all requests would be
proxied.
Now, there's a further refinement in that hostnames can be added
to the `xpack.actions.proxyBypassHosts` and `xpack.actions.proxyOnlyHosts`
config keys. Only one of these config keys can be used at a time.
If the target URL hostname of the HTTP request is listed in the
`proxyBypassHosts` list, the proxy won't be used.
If the target URL hostname of the HTTP request is **NOT** listed in the
`proxyOnlyHosts` list, the proxy won't be used.
Depending on the customer's environment, it may be easier to list the hosts to
bypass, or easier to list the hosts that should only be proxied, so they can
choose either method.
ad06d16beb