fix: openFolder button on Explorer panel

[jsjoeio]

This PR fixes a bug with the "Open Folder" button not working as expected due to a "missing command". The fix is simply using the openFolder command instead of the openFileFolder.

Screenshot

Screen.Recording.2021-07-06.at.2.04.08.PM.mov

Fixes #3457

[codecov]

Codecov Report

Merging #3728 (69277b7) into main (102f811) will not change coverage.
The diff coverage is n/a.

❗ Current head 69277b7 differs from pull request most recent head 990414c. Consider uploading reports for the commit 990414c to get more accurate results

@@           Coverage Diff           @@
##             main    #3728   +/-   ##
=======================================
  Coverage   61.55%   61.55%           
=======================================
  Files          35       35           
  Lines        1813     1813           
  Branches      365      365           
=======================================
  Hits         1116     1116           
  Misses        588      588           
  Partials      109      109           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 102f811...990414c. Read the comment docs.