Harden OData string filter serialization

[wilsonfreitas]

Summary

• add typed OData filter literal serialization
• escape apostrophes in string filter values using OData single-quote escaping
• raise ODataError for unsupported or malformed filter values
• add focused tests for string escaping, dates, decimals, ints, and invalid inputs

Fixes #32

Verification

• uv run pytest -m "not integration" (137 passed, 11 deselected)
• uv run ruff check bcb/ tests/
• uv run ruff format --check bcb/ tests/
• uv run mypy bcb/
• uv run --group docs sphinx-build -b html docs docs/_build/html