feat: add examples for creating and managing LLM projects and tests (#543)

- Introduced `create_llm_project_with_tests.py` to demonstrate LLM project creation and various test types including rubric, character length, PII detection, and row count tests.
- Added `create_project.py` to showcase project creation for different task types (LLM, tabular classification, regression, and text classification) and listing/filtering projects.
- Included detailed print statements for user feedback during execution.

Author: viniciusdsmello