Summary:
`db.create_cf` call `crocksdb_create_column_family`, which doesn't pass titan specific options to titan. Fix it by calling `ctitandb_create_column_family` when titan is enabled.

Test Plan:
Manual test when enabled titan, tikv pass correct titan options when creating new CFs.

Will add unit test in later patch.
Signed-off-by: Yi Wu <yiwu@pingcap.com>