Update Release Pipeline

[aznhassan]

Problem

We need to sign the Visual Studio Code extension as part of the release pipeline

Solution

Use the MicroBuild template along with the signing extension to sign the extension as part of the build stage. I also moved the stage templates into a stages folder, along with a steps folder for the new signing step.

Validation

• Pipeline run example where the build/sign steps ran successfully

Note

• The publish step did not run so there may be another PR after this one to iron out any issues with that stage.
• The prerelease pipeline was left alone since the extension does not support test signing at the moment, but we can still do an extension prerelease that is real signed.
• I could not get the deployment environment to work with the MicroBuild template, so the approval step is now a manual approval not based on the environment.