Add telemetry query at start-up time

We would like to start gathering telemetry on the usage of adapters like django-cockroachdb so that we have some notion of their popularity.

To support this, please add the following query at app start-up time:

SELECT crdb_internal.increment_feature_counter('Django %d.%d')

where the placeholders are the major and minor Django version numbers.

A couple additional details here:

• Ideally the query should be executed once at start-up time. In ActiveRecord we accomplished this by executing the query when the connection pool is initialized but there may be a better spot in Django.
• Depending on the CockroachDB version, the increment_feature_counter built-in may or may not be defined. (We added it in v21.1.) So we should ensure that an error is not bubbled up to the user if the query fails.
• We would like to execute this query by default, but please also add a setting which allows the user to disable it. (In ActiveRecord we called this disable_cockroachdb_telemetry.)

[rafiss]

@vy-ton the hashes are sha256 checksums. they can be found with these commands:

❯ echo 'Django 3.0' | sha256sum
14adb292d2b5f51da817153fa061474f7b9345a55c583bcacfd01e5272e6220e  -
❯ echo 'Django 3.1' | sha256sum
ae10f0770e238b33a8c0ddb1bb6f3b54b3c488dde060ad1cab0aec90ac057fd0  -
❯ echo 'Django 3.2' | sha256sum
f2fce0d91eaf91914068e3f64578fca19b049ec29a5966992fb1977d469877c9  -

[timgraham]

I’m not sure how to get those hashes.