adds HEAD method to gin router

[vrnvu]

PR addresses #436 and adds HEAD for the gin router.

[kpacha]

adding proper support for HEAD requests is not an easy task. HEAD is a 'safe' method but it has some particularities, such as sending a content-length header with the value it would return to a GET request but without the actual body. unfortunately, these particularities do not fit very well on our model. I'll throw here some of the questions I think we should answer before coding a single line:

1- how to deal with composed request? 2- how to deal with changes in the response encoding? 3- how to deal with the response manipulation (mapping, filtering and so on)? 4- how to deal with incomplete responses (when composing)?

finally, the response to a HEAD request shouldn't include a body and your code doesn't deal with that

thanks

[kpacha]

closing due inactivity

[github-actions[bot]]

This pull request was marked as resolved a long time ago and now has been automatically locked as there has not been any recent activity after it. You can still open a new issue and reference this link.