This is useful in the support view in case the audit log data is
stale and user counts are not updated for billing.
Also, renames formatting function for optional datetimes that is
used in the support and activity views/charts. And instead of
showing these datetime strings in the eastern US timezone, we
now show and label them as UTC.
Also, renames `ad_hoc_query.html` to `activity_table.html`,
`realm_summary_table.html` to `installation_activity_table.html`,
and `activity_details_template.html` to `activity.html`.
Removes the style attribute in the installation activity template
and uses a CSS class, "installation-activity-header", to center the
h3 and p tags instead. This removes an exception from the custom
lint check.
View functions in `analytics/views/support.py` are moved to
`corporate/views/support.py`.
Shared activity functions in `analytics/views/activity_common.py`
are moved to `corporate/lib/activity.py`, which was also renamed
from `corporate/lib/analytics.py`.