chore: Use tracing's fields to get structured logs

[jaysonsantos]

This also enables on services that can query this data to get useful metrics.
Also note that I chose db.statement to having a standard to follow even though this does not use opentelemetry, but the latter can benefit from it [1].

Running the tests with that would log something like this:

[2023-02-24T17:14:00Z INFO  sqlx::query] summary="select 1 as \"foo?\"" db.statement="" rows_affected=0 rows_returned=1 elapsed=24.75µs sql=""
[2023-02-24T17:14:00Z INFO  sqlx::query] summary="select 1 as \"foo: …" db.statement="\n\nselect\n  1 as \"foo: MyInt\"\n" rows_affected=0 rows_returned=1 elapsed=44.5µs sql="\n\nselect\n  1 as \"foo: MyInt\"\n"
[2023-02-24T17:14:00Z INFO  sqlx::query] summary="select 1 as \"foo?: …" db.statement="\n\nselect\n  1 as \"foo?: MyInt\"\n" rows_affected=0 rows_returned=1 elapsed=26.208µs sql="\n\nselect\n  1 as \"foo?: MyInt\"\n"
[2023-02-24T17:14:00Z INFO  sqlx::query] summary="select 1 as \"foo!: …" db.statement="\n\nselect\n  1 as \"foo!: MyInt\"\n" rows_affected=0 rows_returned=1 elapsed=22.625µs sql="\n\nselect\n  1 as \"foo!: MyInt\"\n"

[1] https://opentelemetry.io/docs/reference/specification/trace/semantic_conventions/database/#call-level-attributes