ARROW-10167: [Rust] [DataFusion] Support DictionaryArray in sql.rs tests, by using standard pretty printer

[alamb]

This PR removes (most of) the special case pretty printing code in DataFusion's sql integration test, sql.rs in favor of the standard pretty printer in arrow::utils::pretty and in the process adds support for DictionaryArray printing as well as standardizing how tests are run and output is compared.

I am working on adding support for DictionaryArray in DataFusion (and thus want to add tests to sql.rs). This specific PR's changes are larger than strictly necessary, but I felt it made it easier to write new tests in sql.rs. However, if people prefer, I could instead add a special case for DictionaryArray in array_str and accomplish my goal with a much smaller PR

Note: I found that using Vec<Vec<String>> to encode expected results rather than a String retains the nice property that differences to expected output are shown reasonably in the test output. For example:

---- csv_query_cast_literal stdout ----
thread 'csv_query_cast_literal' panicked at 'assertion failed: `(left == right)`
left: `[["0.9294097332465232", "1.0"], ["0.3114712539863804", "1.0"]]`,
right: `[["0.9294097332465232", "1"], ["0.3114712539863804", "1"]]`', datafusion/tests/sql.rs:502:5

[github-actions]

https://issues.apache.org/jira/browse/ARROW-10159

[github-actions]

https://issues.apache.org/jira/browse/ARROW-10167

[alamb]

this is a pretty good example of the change in structure.

[alamb]

Note that this type was missing in pretty.rs (I found it while converting the tests in sql.rs).

[alamb]

I did cheat somewhat here and punt on adding proper ListArray support to pretty.rs.

[andygrove]

Thanks @alamb this is a nice cleanup of the tests.

[jorgecarleitao]

Really nice, @alamb . LGTM

[jorgecarleitao]

@alamb we need a small rebase to merge.

[alamb]

@jorgecarleitao FYI rebased