Add support for EXTERNAL auth

[david-mohr]

Adds an optional mechanism parameter and implements EXTERNAL auth following the Java reference implementation.

Also fixes a broken test.

[icappello]

Hello, thanks for opening this PR! We will give you a feedback in the next few days

[david-mohr]

Just about to head on vacation, so I will be able to make these updates in a few weeks.

[david-mohr]

Is there a way I can run these github actions on my own account? I have not used github actions before, so not familiar with them. Plus I seem to be in a different timezone making it challenging to work on it while you are available.

[icappello]

Hello David, I think you need to enable Actions in your forked repository by visiting the "Actions" tab. You should see a warning with a button to enable workflows.

Here is a discussion regarding this https://github.com/orgs/community/discussions/50736

Thanks again!

[david-mohr]

Thanks for the pointers, the workflow should now be working as expected.

[icappello]

We'll give you a feedback as soon as possible.

Thanks!

[gpad]

@david-mohr Thank for the PR I have added two small comments. WDYT about it?

[david-mohr]

@gpad thanks, updates applied

[david-mohr]

@icappello just curious, do you have an eta on the next release? Happy using my fork for now, but wanted to follow up before I forget. Thanks!