Fixes #1651 - Adds an option to open a file on click in Search & Compare

[EhabY]

Description

Closes #1651. This PR adds an option in the GitLens settings to open the file when clicking on its entry in the Search & Compare instead of opening the diff view.

Since this issue was only for the Search & Compare, I only added this settings for this view. If there is need to add it to the other views then I can do that as well. Supersedes #2845 since that one seems to be stale now.

Checklist

• I have followed the guidelines in the Contributing document
• My changes follow the coding style of this project
• My changes build without any errors or warnings
• My changes have been formatted and linted
• My changes include any required corresponding changes to the documentation (including CHANGELOG.md and README.md)
• My changes have been rebased and squashed to the minimal number (typically 1) of relevant commits
• My changes have a descriptive commit message with a short title, including a Fixes $XXX - or Closes #XXX - prefix to auto-close the issue that your PR addresses