Added list tables feature

[josemazo]

Story ch70779

[Jesus89]

The current implementation does not cover the complete feature, because it does not allow to check the tables using the default_public API key, for example:

set_default_credentials('cartoframes')
list_tables()  # ForbiddenErrorException: Access denied

The original GitHub ticket links the previous implementation using the Python SDK (#1482, https://github.com/CartoDB/cartoframes/blob/v1.0b7/cartoframes/utils/table.py#L19). I think we should follow the same approach here and delegate the request in the DatasetManager:

datasets = DatasetManager(self.auth_client).filter(
    show_table_size_and_row_count='false',
    show_table='false',
    show_stats='false',
    show_likes='false',
    show_liked='false',
    show_permission='false',
    show_uses_builder_features='false',
    show_synchronization='false',
    load_totals='false')
tables = [str(dataset) for dataset in datasets]

Since this implementation does not require the schema I would remove it from thelist_tables function. I like using a DataFrame for the output, btw.

[josemazo]

Ready for review again!