Comparison test framework improvement

[dai-chen]

Creating this issue for followup work on test framework. Will add more to-do items if needed.

1.In our JDBC implementation, getColumnName() returns column original name in SELECT and getColumnLabel returns its alias. But other reference database seems return alias directly from getColumnName().

2.Just found that org.json seems not respect column order in LinkedHashMap. Needs to convert it to list manually.

3.After fixing bugs in our JDBC driver, we need to add dependency for latest artifact in Gradle. One option is to use local path: testCompile files('libs/opendistro-sql-jdbc-1.4.0.0-SNAPSHOT.jar') in build.gradle. In this case, our GitHub Action should check out and build JDBC master branch whenever it runs comparison test.

4.The current test framework passes Java LinkedHashMap and HashSet for schema and data rows in DBResult class. HashMap and ArrayList needs to be used instead for the case of schema in SELECT * and data rows in ORDER BY.

[dai-chen]

The first 2 issue fixes have been merged. Need to figure out how to handle the 3rd issue especially.

[dai-chen]

5.Need minor changes to support MySQL database.

The follow issue may be caused by length of VARCHAR is required in MySQL.

  2> java.lang.IllegalStateException: Failed to create table [kibana_sample_data_flights]
        at __randomizedtesting.SeedInfo.seed([10BD31FCB60C0A4A:F613C15757C860A7]:0)
        at com.amazon.opendistroforelasticsearch.sql.correctness.runner.connection.JDBCConnection.create(JDBCConnection.java:76)
        at com.amazon.opendistroforelasticsearch.sql.correctness.runner.ComparisonTest.loadData(ComparisonTest.java:74)
        at com.amazon.opendistroforelasticsearch.sql.correctness.CorrectnessIT.performComparisonTest(CorrectnessIT.java:60)

        Caused by:
        java.sql.SQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ',Origin VARCHAR,FlightDelay boolean,DistanceMiles float,FlightTimeMin float,Orig' at line 1
            at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:120)
            at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97)
            at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:122)
            at com.mysql.cj.jdbc.StatementImpl.executeUpdateInternal(StatementImpl.java:1335)
            at com.mysql.cj.jdbc.StatementImpl.executeLargeUpdate(StatementImpl.java:2108)
            at com.mysql.cj.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1245)
            at com.amazon.opendistroforelasticsearch.sql.correctness.runner.connection.JDBCConnection.create(JDBCConnection.java:74)
            ... 2 more