Experimental -- v4 provider

[calina-c]

List of PR changes:

• replace old ECIES_PRIVATE_KEY with PRIVATE_KEY. The purpose of the PRIVATE_KEY is not to decrypt, but to identify the Aquarius version when asking for decrypt from Provider
• temporarily added the artifacts folder and artifacts/install.sh script until we have an ocean-contracts release
• where functions depended on the old DDO structure, replace with the new one, e.g. instead of using get_metadata_from_services, we can now use the "metadata" key directly. Other mischellaneous changes related to the structure, as needed (not all listed below):
  • replace the date format with ISO Format
• remove the encrypt_ddo and encrypt_as_hex endpoints and the encrypt_data function
• repurpose the decryptor class to contain utilitaries for “talking to” Provider
• remove metadata contract from events monitor, since there are now multiple contracts
• reconfigure the event logs retrieval in events monitor to filter by topics for MetadataCreated and MetadataUpdated events, regardless of contract
• replace some logic in processors.py to handle the new structure/event arguments
• remove eciespy from dependencies (no longer needed)

Changes in tests:

• remove deployment of datatoken contract
• remove rawddos (pertaining to old processor tests)
• repurpose send_create_update_tx function to use setMetaData
• use v4 samples
• add unit and functional tests where needed

TODOs:

• check_no_urls_in_files -> adapt
• remove curation :D
• check all arguments for events processors are used
• clear v3 samples ?
• add "real" metadata start block: should be taken from barge, but it is not currently written in the address file

[calina-c]