Increases the width of the heatmap gutter glyph
Moves gutter glyphs closer to the code

Adds line fading option to heatmap annotation

And separates the existing Gerrit provider to a new GoogleSource one.

Closes #1953

Adds a GitLens features section to help avoid GitLens+ feeling like a gate

With Node 16, `Intl.DateTimeFormatOptions` seems to no longer honor the `dayPeriod` option and always return the "long" version, so fallback to use the `timeStyle` option if needed