• There exists an issue discussing the need for this PR
• I added new tests for the issue I fixed or built
• I used pnpm run commit instead of git commit

I have created a new sub-package instead of updating most-run to keep the most.js version available. (most.js and most core can be seen as two different and parallels projects).

I have never used Typescript so expect type declarations to be enhanced.

Resolved a minor type problem in isolate with hasownproperty that was blocking building