Fix & update MUT download recipe
Fix & update MUT download recipe

Current recipe run finds no match on the https://jssmut.weebly.com site

- Use `GitHubReleasesInfoProvider` instead
- Add PRERELEASE input variable
- Update description to indicate Github download
- Simplify `input_path` variable in CodeSignature processor since URLDownloader processor uses `pathname` variable for downloaded file path.

autopkg/dataJAR-recipes,autopkg/dataJAR-recipes,autopkg/dataJAR-recipes