Support CLOB and BLOB data types in Db2 [DBZ-4043]

Migrated from [DBZ-4043](https://issues.redhat.com/browse/DBZ-4043)

Created a table named NUMBERS with NUM_CLOB column of the type CLOB, whenever a change record is produced, this field contains the value "null" in the payload.

For example,
{quote}update numbers set num_clob = 'yossi';
{quote}
Is represented:
{quote}\"after\":\{\"NUM_ID\":22,\"NUM_INT\":1,\"NUM_BIGINT\":1,\"NUM_SMALLINT\":1,\"NUM_FLOAT\":11.103,\"NUM_REAL\":9.15,\"NUM_DOUBLE\":10.52,\"NUM_NUMERIC\":\"Cw==\",\"NUM_TS\":1632722730524701,\"NUM_CLOB\":null}
{quote}
According to the documentation, this type is supported and should be treated as String.