Draft: Fix return types of some Surreal methods

[Wouterkoorn]

Change some return types from List[Dict, Any] to Unions[Dict[str, Any], List[Dict, Any]], or the Optional[...], variant of that.

What is the motivation?

Fix the currently incomplete/wrong return type annotations of some Surreal (WS/RPC client) methods.
Improving developer experience of users.

Type of Change

• 📚 Examples / docs / tutorials / dependencies update
• 🔧 Bug fix (non-breaking change which fixes an issue)
• 🥂 Improvement (non-breaking change which improves an existing feature)
• 🚀 New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to change)
• 🔐 Security fix

What does this change do?

Changes the return type of some methods from List[Dict[str, Any]] to

• Union[Dict[str, Any], List[Dict[str, Any]]] for create, update, and merge
• Optional[Union[Dict[str, Any], List[Dict[str, Any]]]] for select and delete

What is your testing strategy?

mypy returned OK
pre-commit returned OK
./scripts/run_tests.sh returned OK

Is this related to any issues?

Yes: #97
This PR is regarding the first "1." propose solution in the above referenced issue.

Have you read the Contributing Guidelines?

• I have read the Contributing Guidelines

[maxwellflitton]

@Wouterkoorn thanks for this PR, I will work on the conflicts and get this merged. Sorry for the late reply as I have been working on some other areas.

[tobiemh]

Closing this pull-request as the latest codebase has now been significantly updated, now making use of a native Python with binary communication with remote databases, and support for embedded database usage. The native Python library now has support for custom types, including datetimes, durations, decimals, geojson types, Record IDs, ranges, and tables 🎉.