Limit length of `db.query.summary`?

[trask]

In Java Instrumentation repo, we've had reports of query texts of 15mb.

I think it may be ok(?) to capture the full value under db.query.text and users can rely on the general attribute limit to truncate

But I think it may make sense to apply some kind of limit to db.query.summary (or at least to the resulting span name when it is based on db.query.summary).