Support table with `_hoodie_operation` meta field

When prepend meta fields, current impl assumes there is no `_hoodie_operation`. When table uses this field, it should be handled properly.

Start by locating the implementation that prepends meta fields and any existing tests for table metadata. Reproduce the behavior with a table containing `_hoodie_operation`, then establish the expected handling from the surrounding implementation. Done means the code no longer assumes this field is absent and tests cover the case.

Written by the indexing model from the issue text.