Fix editor endpoint to open sourcegraph links

Created by: abeatrix

Currently, our editor endpoint is adding ine range as url fragment (link to code) that does not support image preview (report by a user here). We have hardcoded the way we generate the redirect URL in the VS Code extension as a temporary workaround but unfortunately, it does not work for all cases (eg https clone link vs ssh clone link). This PR is to fix the editor endpoint so that we could use the editor enpoint to generate a URL in the correct format that supports image preview.

Adding line range to the end of URL as string has resolved the issue: (Note: deploy-sourcegraph was cloned using ssh & sourcegraph repo was cloned using https.)