fix: improve decorated tool output

[michael-desmond]

1. Replaces to_string on tool output with python str override
2. Tool results are now printed in agents notebook
3. Decorated tools that return str can now work with Agent (output is wrapped as StringToolOutput)
4. Error checking in notebooks for search tool failures

Checklist

• I have read the contributor guide
• I have signed off on my commit
• Linting passes: yarn lint or yarn lint:fix
• Formatting is applied: yarn format or yarn format:fix
• Unit tests pass: yarn test:unit
• E2E tests pass: yarn test:e2e
• Tests are included
• Documentation is changed or added
• Commit messages and PR title follow conventional commits

[vabarbosa]

should this also check if result is dict then use JSONToolOutput else default to StringToolOutput?

[vabarbosa]

now that we have JSONToolOutput isnt the output from OpenMeteo more accurately a JSONToolOutput instead of StringToolOutput?