Format SQL queries when printing them to the logs

Before, the query would be formatted equivalent to the input string:

```
[2020-04-18T23:47:32Z DEBUG sqlx_core::postgres::executor] SELECT id, queue, ..., elapsed: 2.320µs

        SELECT id, queue, payload, status, priority, created_at, updated_at
    FROM jobs
    WHERE status = $1
    ORDER BY priority ASC, created_at ASC

```

After, the query is formatted cleanly and consistently:

```
[2020-04-19T00:30:18Z DEBUG sqlx_core::postgres::executor] SELECT id, queue, ..., elapsed: 2.280µs

    SELECT
      id,
      queue,
      payload,
      status,
      priority,
      created_at,
      updated_at
    FROM
      jobs
    WHERE
      status = $1
    ORDER BY
      priority ASC,
      created_at ASC

```

This uses the `sqlformat` crate, which was ported from the
Javascript `sql-formatter-plus` library specifically for this purpose.

sqlx-core/Cargo.toml

@@ -66,6 +66,7 @@ uuid = { version = "0.8.1", default-features = false, optional = true, features
 serde = { version = "1.0", features = [ "derive" ], optional = true }
 time = { version = "0.2.7", optional = true }
 serde_json = { version = "1.0", features = [ "raw_value" ], optional = true }
+sqlformat = "0.1.0"
 
 # <https://github.com/jgallagher/rusqlite/tree/master/libsqlite3-sys>
 [dependencies.libsqlite3-sys]

sqlx-core/src/logging.rs

@@ -8,17 +8,25 @@ macro_rules! log_execution {
         let elapsed = timer.elapsed();
         if elapsed >= std::time::Duration::from_secs(1) {
             log::warn!(
-                "{} ..., elapsed: {:.3?}\n\n    {}\n",
+                "{} ..., elapsed: {:.3?}\n\n{}\n",
                 crate::logging::parse_query_summary(query_string),
                 elapsed,
-                query_string
+                sqlformat::format(
+                    query_string,
+                    &sqlformat::QueryParams::None,
+                    sqlformat::FormatOptions::default()
+                )
             );
         } else {
             log::debug!(
-                "{} ..., elapsed: {:.3?}\n\n    {}\n",
+                "{} ..., elapsed: {:.3?}\n\n{}\n",
                 crate::logging::parse_query_summary(query_string),
                 elapsed,
-                query_string
+                sqlformat::format(
+                    query_string,
+                    &sqlformat::QueryParams::None,
+                    sqlformat::FormatOptions::default()
+                )
             );
         }
         result