[feat] Allow mapping HEAD method when calling MapQuery()

[ikesnowy]

Is your feature request related to a problem? Please describe.

Needs a way to make query support GET and HEAD methods

Server:

app.MapQuery<GetItemQuery>("/items/{key}");

ServiceAgent.HasItemAsync():

var request = new HttpRequestMessage(HttpMethod.Head, "/items/1");
var response = await _httpClient.SendAsync(request);
return response.IsSuccessfulStatusCode;