feat(export_to_file): add multiple where conditions

[jardabezdek]

Currently, Client.tables.export_to_file supports one where condition for one column only:

sapi-python-client/kbcstorage/tables.py

Lines 362 to 392 in c67dd40

	def export_to_file(self, table_id, path_name, limit=None,
	file_format='rfc', changed_since=None,
	changed_until=None, columns=None,
	where_column=None, where_values=None,
	where_operator='eq', is_gzip=True):
	"""
	Export data from a table to a local file
	Args:
	table_id (str): Table id
	path_name (str): Destination path for file.
	limit (int): Number of rows to export.
	file_format (str): 'rfc', 'escaped' or 'raw'
	changed_until (str): Filtering by import date
	Both until and since values can be a unix timestamp or any
	date accepted by strtotime.
	changed_since (str): Filtering by import date
	Both until and since values can be a unix timestamp or any
	date accepted by strtotime.
	where_column (str): Column for exporting only matching rows
	where_operator (str): 'eq' or 'neq'
	where_values (list): Values for exporting only matching rows
	columns (list): List of columns to display
	is_gzip (bool): Result will be gzipped
	Returns:
	destination_file: Local file with exported data
	Raises:
	requests.HTTPError: If the API request fails.
	"""

Please, add option to add multiple where conditions over multiple columns into the method.