Bach: support arbitrary names for Series

[thijs-obj]

Names for Series are currently limited by the column names that a database supports, because Series names map directly to column names.

We want to remove this limitation.

Discussed approach:

• Series is responsible for going from 'real-name' to 'column-name'
• Column name translation algorithm should work both ways
• Should be transparent to user (as long as user doesn't look at or use the generated SQL)

[thijs-obj]

Make sure to enable tests that are now skipped for Athena and BigQuery based on this limiations. Some tests( not complete!):

• bach/tests/functional/bach/test_df_setitem.py::test_set_series_column_name_with_spaces() for all databases afterwards
• see this PR for another test https://github.com/objectiv/objectiv-analytics/pull/1223
• bach/tests/functional/bach/test_df_rename.py
• Search the code base for https://github.com/objectiv/objectiv-analytics/issues/1209
• Search the code base for #1209

[ivarpruijn]

Is this issue resolved @thijs-obj ?

[thijs-obj]

Yes. ~There is still one sub-issue open https://github.com/objectiv/objectiv-analytics/issues/1317, but it's low prio and the main issue can be considered to be solved.~

edit: Actually completely solved