Add support for gopass

[Moghi]

I have added support for gopass based on pass, The only thing I had to change was to get rid of the base64 encoding of the server URL, gopass couldn't deal with any = in name while doing gopass insert name.

[GordonTheTurtle]

Please sign your commits following these rules:
https://github.com/moby/moby/blob/master/CONTRIBUTING.md#sign-your-work
The easiest way to do this is to amend the last commit:

$ git clone -b "master" [email protected]:Moghi/docker-credential-helpers.git somewhere
$ cd somewhere
$ git commit --amend -s --no-edit
$ git push -f

Amending updates the existing PR. You DO NOT need to open a new one.

[mcnesium]

is @Moghi ever going to sign this?

[Moghi]

I don't think so, to be honest.

[sudoforge]

For those who are viewing this PR in an effort to find gopass support:

I submitted a pull request in May of 2023 to add initial support for gopass. This was a slight fork off of this PR, which touched up on a couple of issues.

There was some initial back and forth with requested changes, which were implemented.

Over the past year, however, there has been no maintainer feedback on the PR. To support people who use gopass (myself included), I have been actively maintaining a fork that is regularly rebased on top of docker/docker-credential-helpers (manually atm, but if the PR continues to stall I'll automate this).

You are more than welcome to use my fork of this repository if you need or want gopass support.