SQLite Observer & Exporter for SQLite

This provides a fairly simple SQLite powered backend for the metrics crate, useful for offline or desktop applications to gather metrics that can be easily queried afterwards.

Example

Example using metrics_runtime crate & sampling the metrics every 1s:

```Rust let receiver = Receiver::builder() .build() .expect("failed to create receiver");

let mut exporter = SqliteExporter::new( receiver.controller(), SqliteBuilder::new(), Duration::from_secs(1), "metrics.db", ) .expect("Failed to create SqliteExporter"); receiver.install(); exporter.run(); ```