AnyQueryResult does not map last_insert_id correct

[thegenius]

Bug Description

I found sqlx does not map QueryResult correctlly for postgres and sqlite

1. PgQueryResult map last_insert_id to None

fn map_result(res: PgQueryResult) -> AnyQueryResult {
    AnyQueryResult {
        rows_affected: res.rows_affected(),
        last_insert_id: None,
    }
}
2. SqliteQueryResult map last_insert_id to None
```rust
fn map_result(res: SqliteQueryResult) -> AnyQueryResult {
    AnyQueryResult {
        rows_affected: res.rows_affected(),
        last_insert_id: None,
    }
}



### Minimal Reproduction



### Info
* SQLx version: [REQUIRED]
* SQLx features enabled: [REQUIRED]
* Database server and version: [REQUIRED] (MySQL / Postgres / SQLite <x.y.z>)
* Operating system: [REQUIRED]
* `rustc --version`: [REQUIRED]