Biglist

- ``BiglistBase`` now has custom support for pickling.
- Minor improvements to doc.

- New method ``Biglist.make_file_name``, which allows user to insert custom content in the file names.

- Bug fix in Parquet schema.
- Increased default value of ``Biglist._n_write_threads`` from 3 to 8.
- Increased default timeout to ``_util.lock_to_use`` from 120 to 300.
- Bugfix: previously, exceptions in file writing (happening in background threads)
in ``_biglist.Dumper`` are not propagated; now they are re-raised in
``Dumper.wait``, which is called by ``Biglist.flush``.

- Small refinements.
- Removed ``write_parquet_file``.
- Default ``batch_size`` for ``Biglist`` reduced from 10_000 to 1_000. Warning is issued if user does not specify ``batch_size``.
- Bugfix related to closing a ``ParquetFile`` in ``_parquet.ParquetFileReader.load_file``.
Removed a "lazy" workaround related to this bug.
- Removed dependency on ``mpservice``.

- Upgrade ``mpservice``.

Fixed

- ``write_parquet_table`` bug: ``ParquetBiglist.get_gcsfs`` should be ``ParquetFileReader.get_gcsfs``.