Split off matUtils commands

[aofarrel]

This repo badly needs to be split, but three workflows within it are on Dockstore. Here's the general approach:

• Copy matUtils workflows into the new repo
• Double check they still work
• Make a .dockstore.yml for the new repo
• In this PR, modify the matUtils workflows' workflow-level readmes to point to their new repo version
• Merge PR
• Tag that commit
• Set the default version for the Tree Nine version of the matUtils workflows to the tagged commit, so their Dockstore readmes all point to the new version
• In a different PR, remove the workflows from Tree Nine and their entries from the Tree Nine .dockstore.yml
• Make another tagged commit