Fix issue where editing a Nunjucks variable/tag didn't update environment variables

[tlund101]

This is a small PR that fixes behavior when setting environment variables via the tag/variable modal.
Reproduction steps:

1. Create a new environment
2. Add a property whose value is a variable (e.g. I used a timestamp)
3. Create a request using the new property, observe the request is using your property correctly
4. Edit the environment again, and click the value to open the tag modal
5. Change the value to something different/invalid, close the modal by clicking Done
6. Close the environment modal by clicking Done
7. Observe the property in your request did not change

This is somewhat of a naive solution, so I'm open to suggestions to fix this better. Notably, why is this component not simply saving onChange if there are no errors instead of onBlur if there are no errors?

[jackkav]

We save onBlur because saving onChange will cause all the background components to re-render on every keypress.

[tlund101]

We save onBlur because saving onChange will cause all the background components to re-render on every keypress.

Thanks for the insight. I've modified the PR to change the CodeEditor instead to call OnBlur when something changes but it isn't in focus. Let me know what you think.

[CLAassistant]

All committers have signed the CLA.