v0.13.0

Changes:

• Migrated from peppy to peprs across all modules (project, sample, view, models, utils)
• Updated subsample key constant: SUBSAMPLE_RAW_LIST_KEY → SUBSAMPLE_RAW_DICT_KEY
• Added alembic database migration support; run_migrations parameter added to PEPDatabaseAgent and BaseEngine
• Fixed nullable fields in schema models (SchemaVersionAnnotation, SchemaRecordAnnotation, UpdateSchemaRecordFields, UpdateSchemaVersionFields)
• Added support for "latest" schema version resolution when uploading/updating projects
• Moved SAMPLE_NAME_ATTR and SAMPLE_TABLE_INDEX_KEY constants into pepdbagent/const.py
• Performed code cleanup and refactoring across modules, including modernization of the codestyle, installation and dependencies.
• ❗get_raw method (returning raw project) now returns keys: {config, samples, subsamples} instead of {config, sample_list, subsample_list}