feat: add more details to postgrest spans

[adityathebe]

resolves: #829

The otel echo middleware doesn't offer the flexibility to customize the span name.

[moshloop]

@adityathebe can we make the span name /db/table_name ?

[adityathebe]

@adityathebe can we make the span name /db/table_name ?

@moshloop I don't think the echo otel middleware allows it

https://github.com/open-telemetry/opentelemetry-go-contrib/blob/a6c39275e680e3316303c2f6210d1cc5fb1752cf/instrumentation/github.com/labstack/echo/otelecho/echo.go#L70-L76

Should we fork it?

[moshloop]

@adityathebe it is not that important for now