Implements an `--all` flag for a src directory to consider
for coverage. If supplied, c8 will glob the directory respecting the
`--include` and `--exclude` parameters for src files. All source files
will be included in the final report. If a file is not found in the
v8 coverage output, it will be initialized with an empty v8 record and
reported as 0 lines/branches/functions covered.

Note: This uses the empty v8 approach instead of the empty report approach

Fix html report

--all should be boolean

Update snapshot

fix async function

WIP - changing --all a bit to create a fake v8 coverage entry and additional args changes

WIP - read source maps for faked entries

WIP

WIP

Moved approach to empty v8 blocks