Automated extension publishing using GitLab publisher

This MR introduces 3 changes:

• Replaces the references to fatihacet publisher with GitLab publisher.
• Introduces CI job publish that can be run on tags and it will publish the extension.
• Adds the AZURE_ACCESS_TOKEN environment variable to the CI config
• Changing the support email to the Service Desk email for this project

I've configured this CI before and used it for publishing in 2 of my personal projects:

• https://gitlab.com/viktomas/slipbox/-/pipelines/154713636
• https://gitlab.com/viktomas/gitlab-example-extension/-/pipelines/146890018

Azure access token

I followed the Official guide to create the token.

But I didn't give the token full access to manage the publisher, only "publish" rights.

So I'm not 100% confident the publishing will work first at the first try. In the worst-case scenario, I'll create a new token with higher access rights and rerun the publish job.

The access token is added to the CI configuration:

This is a copy of an MR we used for the 2.2.1 security release (GitLab internal access needed) https://gitlab.com/gitlab-org/security/gitlab-vscode-extension/-/merge_requests/2.

Closes #171 (closed)