Revert "Unify variable viewer data types (#15038)"

[amunger]

This reverts commit 14fc23d695bbabc4bf851815537c31e031ab3304.

Fixes #

• [ ] Pull request represents a single change (i.e. not fixing disparate/unrelated things in a single PR).
• [ ] Title summarizes what is changing.
• [ ] Appropriate comments and documentation strings in the code.
• [ ] Has sufficient logging.
• [ ] Has telemetry for feature-requests.
• [ ] Unit tests & system/integration tests are added/updated.
• [ ] Test plan is updated as appropriate.
• [ ] package-lock.json has been regenerated by running npm install (if dependencies have changed).