Add conda hash to mulled-hash utility

[natefoo]

Despite the overlap in mulled-v1- naming, the v1_image_name in mulled.util is not actually used for conda v1 mulled hashes. Perhaps it should, since as far as I know, we never used the container mulled v1 hash for anything, but that's another issue.

How to test the changes?

(Select all options that apply)

• [ ] I've included appropriate automated tests.
• [ ] This is a refactoring of components with existing test coverage.
• [x] Instructions for manual testing are as follows:

  1.  $ mulled-hash --hash conda bedtools=2.30.0,samtools=1.9
      mulled-v1-ca195b12c14e35565e393a2d07f2deac7610d8126cc3460d217504efd11d4347
     

License

• [x] I agree to license these and all my past contributions to the core galaxy codebase under the MIT license.