ci: enforce use or fully qualified import style consistency

[darioush]

Our codebase is inconsistent in using import styles, we prefer the top import for new code, but in some cases it's too disruptive to the existing files to break the pattern in an unrelated change.

We should either:
Option A. Take a one time migration cost and always use top import style, enforced in CI,
Option B. Move the decision for which import can be use or top to CI (we can use some simple AI or scripting to automate it, like checking what % of imports in file are fully qualified.)
Option C. Make a list of files that are exceptions to the top import rule.