* Fixed metadata conversion util to extract schema from `HoodieCommitMetadata`
* Fixed failure to fetch columns to index in empty table
* Abort indexing seq in case there are no columns to index
* Fallback to index at least primary key columns, in case no writer schema could be obtained to index all columns
* Fixed `getRecordFields` incorrectly ignoring default value
* Make sure Hudi metadata fields are also indexed
1b6e201160