Add query appender

[daviddallakyan2005]

Stacked on #586. Please merge that first.

GitHub has to target main until the parent PRs land, so the Files tab will also show those slices. Slice only:

daviddallakyan2005:appender-chunks...daviddallakyan2005:appender-query

Adds conn.appender_query(query, types, names=None, table_name=None), wrapping C++ QueryAppender. The default table name is appended_data.

Follows #369

append() converts each cell to a Value and uses the C++ row Append API. Use append_chunk for bulk inserts, which writes into vectors in place.

How to test

OVERRIDE_GIT_DESCRIBE=v1.5.5
.venv/bin/pytest tests/fast/test_appender.py tests/fast/test_appender_chunk.py tests/fast/test_appender_query.py -q

tests/fast/test_appender_query.py: 2 passed. Parent appender tests still pass.

On the full stack: 21 passed across appender, insert, context manager, and module tests. tests/fast excluding spark: 1655 passed.