Push stats information on database upgrade

[frankrousseau]

Problem

There is no way to know how many Kitsu installations exist.

Solution

When a database upgrade is performed, it pushes anonymized statistics to the CGWire telemetry service to allow to know:

• The number of studios using Kitsu
• The number of users
• The number of previews posted
• The number of comments posted

[EvanBldy]

Thanks !