Comments: Track comment editor opened.

[ScoutHarris]

This fixes an issue where opening the new edit Comment view was not tracked.

To test:

• On a real device, go to My Site > Comments > Comment details > Edit.
• Verify this is logged: 🔵 Tracked: comment_editor_opened <blog_id: xxx, comment_id: xxx, context: sites, post_id: xxx, site_type: blog>

Regression Notes

1. Potential unintended areas of impact
   n/a

2. What I did to test those areas of impact (or what existing automated tests I relied on)
   n/a

3. What automated tests I added (or what prevented me from doing so)
   n/a

PR submission checklist:

• I have completed the Regression Notes.
• I have considered adding unit tests for my changes.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

[peril-wordpress-mobile]

You can trigger an installable build for these changes by visiting CircleCI here.

[dvdchr]

LGTM!

[ScoutHarris]

Thanks @dvdchr !