Idea for new Feature: Coverage report

[Davidyz]

With the Snacks profiler being able to track the caller location for functions and scripts, would it be possible to expand it to be able to generate a code coverage report (percentage and line numbers of source code covered by tests)? For vanilla Vimscript, there's covimerage, but for Neovim Lua, we don't have a coverage report tool.

This can be helpful for CI as well, because plugin authors can see whether a new patch is tested or not (via something like codecov.io).