The navigator binary depended on the current git-revision. The issue is
that any target/test depending on the git-revision will have to be
rebuilt/rerun on every commit.

The navigator package itself was careful to avoid unnecessary
rebuilds/reruns. However, the SDK release tarball depends on the
navigator binary and thereby on the git-revision. The daml-assistant
integration tests, which depend on the SDK release tarball, therefore
had to be rerun on every commit.

This change removes the git-revision from the navigator alltogether. For
issue reporting the SDK version is still available.

Previously the revision was used as an ETag to control browser caching, this is now changed to use the SDK version. For development that is too coarse and manual reload will be required during development, the navigator README has been updated to mention this.

The git-revision target and workspace status scripts are no longer used anywhere and have been removed.

Pull Request Checklist

• Read and understand the contribution guidelines
• Include appropriate tests
• Set a descriptive title and thorough description
• Add a reference to the issue this PR will solve, if appropriate
• Add a line to the release notes, if appropriate
• Normal production system change, include purpose of change in description

NOTE: CI is not automatically run on non-members pull-requests for security
reasons. The reviewer will have to comment with /AzurePipelines run to
trigger the build.