Add case-insensitive getters on resultSet

[egillax]

I believe the getters for resultSet should be case insensitive:

Column names used as input to getter methods are case insensitive.

From here

I'm having an issue where I'm adding duckdb support to an application that already supports a number of other database systems through jdbc. There the results are always fetched like:

resultSet.getString('VERSION') 

for a column version. This currently doesn't work in duckdb.

[Mause]

Probably just needs a change here?

duckdb-java/src/main/java/org/duckdb/DuckDBResultSet.java

Line 314 in dedf7b7

if (meta.column_names[col_idx].contentEquals(columnLabel)) {

[jghoman]

Probably just needs a change here?

That worked. Added change and unit test.