HMAC authenticaion method

[OndraM]

Only a basic building block of client internals.

Will be used as custom authentication method of HTTPlug Authentication plugin.

Something like

new PluginClient(
    HttpClientDiscovery::find(),
    [
        new AuthenticationPlugin(new HmacAuthentication($this->apiKey)),
    ]
);

(This will be part of Matej\Client internals, so end-clients will not have to set it up.)

[jirinovak]

Maybe getAuthenticationParams or createAuthenticationParams would be better names.

[OndraM]

I've been thinking about this one before and also considered both of those suggestions. But I didn't like them as well - the params are actually being added to params already present in Request. So they are not being created, nor just "get" (get = no side effects). But I don't like addAuthenticationParams either.

So what about addAuthenticationToParamsFromRequest($request)?