Support substring with three arguments: (str, from, for) for DataFrame API and Ballista

[yjshen]

It would be nice if we also support three arguments substring for Ballista.

substring impl: https://github.com/apache/arrow-datafusion/blob/master/datafusion-physical-expr/src/unicode_expressions.rs#L413

For DataFrame API: https://github.com/apache/arrow-datafusion/blob/master/datafusion-expr/src/expr_fn.rs#L256

For Ballista: https://github.com/apache/arrow-datafusion/blob/master/datafusion-proto/src/from_proto.rs#L1138-L1141

[Ted-Jiang]

@yjshen i think it already in ballista

C02DM20AMD6T arrow-datafusion % cargo run --bin datafusion-cli --features ballista -- --host localhost --port 50050
   Compiling ballista-core v0.6.0 (/Users/yangjiang/CLionProjects/github/arrow-datafusion/ballista/rust/core)
   Compiling ballista v0.6.0 (/Users/yangjiang/CLionProjects/github/arrow-datafusion/ballista/rust/client)
   Compiling datafusion-cli v7.0.0 (/Users/yangjiang/CLionProjects/github/arrow-datafusion/datafusion-cli)
    Finished dev [unoptimized + debuginfo] target(s) in 16.47s
     Running `target/debug/datafusion-cli --host localhost --port 50050`
DataFusion CLI v7.0.0
❯ select substr('alphabet', 3,2);
+--------------------------------------------+
| substr(Utf8("alphabet"),Int64(3),Int64(2)) |
+--------------------------------------------+
| ph                                         |
+--------------------------------------------+
1 row in set. Query took 0.231 seconds.
❯

[yjshen]

Thanks, my fault.