Add bindings for sqlite3_trace_v2 API

[WesleyAC]

The trace feature flag currently enables the deprecated tracing functions. It should provide access to the new sqlite3_trace_v2 API as well.

[gwenn]

rusqlite/src/trace.rs

Line 120 in b41bd80

// TODO sqlite3_trace_v2 (https://sqlite.org/c3ref/trace_v2.html) // 3.14.0, #977

And the old functions seem not really deprecated at least on this page:
http://sqlite.org/c3ref/funclist.html

functions whose names are struck through are deprecated.

[WesleyAC]

Interesting point, reported on the SQLite forum. Either way, I'd like access to the v2 API, since it structures the data in a way that's nicer for generating spans to integrate into my tracing system, which is what I want to do.

Should this issue be merged into #977, or kept separate?

[gwenn]

You can keep it separate.

[sgbeal]

Interesting point, reported on the SQLite forum.

The upstream doc generator now knows that sqlite3_trace() and sqlite3_profile() are deprecated and will flag them as such the next time the site is rebuilt (which typically happens as a release approaches). Thank you for the report.