fix: call render operator function

[eschutho]

SUMMARY

Found a small bug where the render operator function was being passed in instead of executed and so the operator was undefined. I just renamed the variable so that it would sound more like a method to make it easier to catch in the future. Also added some tests.

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

Before:

After:

TESTING INSTRUCTIONS

Add a color condition to a column on the table viz

ADDITIONAL INFORMATION

• Has associated issue:
• Required feature flags:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API

[sadpandajoe]

LGTM

[rusackas]

Thanks!