Moved bundle_id to ids and aggregated ExtensionPointID onto enumeration class

Created by: stefanoborini

Extracted the bundle_id and the extension point ids due to their shared nature.

Fixes #24 (closed)

force_bdss/core_plugins/csv_extractor/csv_extractor/csv_extractor_bundle.py

 from traits.api import provides, HasStrictTraits, String
 
-from force_bdss.api import bundle_id, IDataSourceBundle
+from force_bdss.api import IDataSourceBundle, bundle_id
 
 from .csv_extractor_model import CSVExtractorModel
 from .csv_extractor_data_source import CSVExtractorDataSource