feat: `bigframes.options` and `bigframes.option_context` now uses thread-local variables to prevent context managers in separate threads from affecting each other#652

tswast merged 12 commits intomaingoogleapis/python-bigquery-dataframes:mainfrom

b308657813-thread-local-option_contextgoogleapis/python-bigquery-dataframes:b308657813-thread-local-option_contextCopy head branch name to clipboard