Destination Google Sheets: clears rows, should delete rows

## Environment
- **Destination Connector and version**: 0.1.2
- **Step where error happened**: Sync job

## Current Behavior
Full refresh/Overwrite: Destination sheet progressively fills with empty rows over time

## Expected Behavior
Destination sheet should not fill with empty rows over time

## Exact problem code:
In spreadsheet.py, the clean_worsheet() method calls the pygsheets clear() method

In writer.py, the write_from_queue() method calls the pygsheets append_table() method

The clear() method doesn't remove rows, it only empties them.

So the sync inserts new rows but doesn't remove the previous rows.

clean_worksheet() should probably call the pygsheets delete_rows() method instead of clear()