Code / texteditor should do background go imports updates and refresh just that section

[rcoreilly]

Describe the feature

goimports can be horribly slow when there are errors that look like packages it doesn't know about. Unfortunately this is a very frequent occurrence, and is the major reason why the Go mod switch is so important when doing major refactoring.

Also, .goal code needs to get its imports from generated .go code, so need special logic for that.

Relevant code

No response