Add support for ResultSet.getBlob() calls when working with WKB_BLOB types

[lukaseder]

Run this program:

try (Statement s = connection.createStatement()) {
    s.executeUpdate("install spatial");
    s.executeUpdate("load spatial");
}

try (Statement s = connection.createStatement();
    ResultSet rs = s.executeQuery("select st_aswkb(cast('point (1 2)' as geometry))")
) {
    while (rs.next()) {
        Blob b = null;

        try {
            b = rs.getBlob(1);
            System.out.println(Arrays.toString(b.getBytes(1, (int) b.length())));
        }
        finally {
            if (b != null)
                b.free();
        }
    }
}

It errors as follows:

0
getBlob
null
java.sql.SQLFeatureNotSupportedException: getBlob
	at org.duckdb.DuckDBVector.getBlob(DuckDBVector.java:284)
	at org.duckdb.DuckDBResultSet.getBlob(DuckDBResultSet.java:514)
	at org.jooq.testscripts.JDBC.main(JDBC.java:48)

This is because the WKB_BLOB type isn't supported by org.duckdb.DuckDBColumnType, and thus org.duckdb.DuckDBResultSetMetaData.TypeNameToType(String) can't look up the type name.

A workaround is to cast as ordinary BLOB or use a different function, such as st_ashexwkb:

try (Statement s = connection.createStatement()) {
    s.executeUpdate("install spatial");
    s.executeUpdate("load spatial");
}

try (Statement s = connection.createStatement();
    ResultSet rs = s.executeQuery("select cast(st_aswkb(cast('point (1 2)' as geometry)) as blob)")
) {
    while (rs.next()) {
        Blob b = null;

        try {
            b = rs.getBlob(1);
            System.out.println(Arrays.toString(b.getBytes(1, (int) b.length())));
        }
        finally {
            if (b != null)
                b.free();
        }
    }
}

This prints:

[1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, -16, 63, 0, 0, 0, 0, 0, 0, 0, 64]

According to the docs:
https://duckdb.org/docs/extensions/spatial

"with the type WKB_BLOB (which can be cast to BLOB) instead of GEOMETRY"

This topic isn't documented very thoroughly, but I think it's reasonable to read between the lines that WKB_BLOB is safe to be treated as an ordinary BLOB when reading the value.