Updates addressing multiple issues

This PR addresses #17, #18, #19, #21, #22, #23, and #24.

Include entity_branch-extension.dic
Update mmcif_ma-data.dic
Update enumerations for _ma_associated_archive_file_details.file_format and _ma_template_details.template_entity_type
Add ma_template_branched category and _ma_target_ref_db_details.is_primary data item
Add _ma_target_ref_db_details.db_accession to the primary key of ma_target_ref_db_details
Update the category description of ma_qa_metric_local_pairwise
Deprecate _ma_model_list.model_id in favor of _ma_model_list.ordinal_id and make _ma_model_list.model_id not mandatory
Update parent-child relationships of all child data items pointing to _ma_model_list.model_id to point to _ma_model_list.ordinal_id
Deprecate _ma_model_list.model_group_id and _ma_model_list.model_group_name
Add ma_model_group, ma_model_group_link, ma_model_representative
Update enumerations for _ma_qa_metric.mode and _ma_qa_metric.type
Update enumerations for _ma_associated_archive_file_details.file_content and _ma_entry_associated_files.file_content
Add ma_feature_list, ma_atom_feature, ma_poly_residue_feature, ma_entity_instance_feature
Add ma_qa_metric_feature, ma_qa_metric_feature_pairwise

ihmwg / ModelCIF