Google Sheets Destination: lock other threads while adding new records

[pauloouriques]

Change description

This PR adds the lock to avoid 2 threads adding records at the same time.

Checklists

Development

• Application changes have been tested appropriately

Impact

• Code follows company security practices and guidelines
• Security impact of change has been considered
• Performance impact of change has been considered
• Possible migration needs considered (model migrations, config migrations, etc.)

Please explain any security, performance, migration, or other impacts if relevant:

Code review

• Pull request has a descriptive title and context useful to a reviewer. Screenshots or screencasts are attached where applicable.
• Relevant tags have been added to the PR (bug, enhancement, internal, etc.)

[bleonard]

some changes, but 🟢 assuming you've tested a few threads at once in the UI.