`discourse-common` was created in the past to share logic between the
'wizard' app and the main 'discourse' app. Since then, the wizard has
been consolidated into the main app, so the separation of
`discourse-common` is no longer useful.
This commit moves `discourse-common/(lib|utils)/*` into
`discourse/lib/*`, adds shims for the imports, and updates existing
uses in core.
Followup 14b436923c5b582cea454b69441a28e16f2f191e
On the standalone Site Traffic report page, we also need
to hide the 'other' and 'crawler' pageviews by default
like we do on the admin dashboard.
Note that this commit will also disable daily grouping for datasets with more than 30 data points. This will also smartly do the grouping by month when grouping a full year.
