Remove unused feature commands

[CrendKing]

PR Summary

Issue report is #3586. These two commands are unused except a dispose() call (I suppose these are the remnants of some historical refactoring?) In the generated js file, the declarations are gone, but the calls to dispose() remain, which causes the extension's dispose() to fail.

I suppose alternatively we could tweak how js files are generated and not optimize out unused variables, but that could have way more footprint than removing them. However, if these variables are still used in some way, you guy decide how to proceed.

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[ghost]

All CLA requirements met.

[andyleejordan]

Also please sign the CLA! I'd love to take this PR today. Thanks so much!

[andyleejordan]

Thanks so much @CrendKing!