Feature/upgrade instrument, right_registry and usage_log contract

[surabhil]

• Upgrades to ore.instrument, ore.rights_registry and ore.usage_log

  • Use Action and Table macros
  • initialize classes with initalising the new base constructor of eosio::contract
  • Initialize indexes in the constructor
  • typedef mutlindexes
  • replace account_name with name
  • use symbol_code and its related methods instead of symbol_name
  • use "_n to get the name instead of N{
  • use account_name.value to get uint64_t representation of account name
  • use new permission level object
  • replace deprecated types.hpp with transaction.hpp
  • replace deprecated time type with time_point_in_sec
  • add comments and update eosio_assert messages

• Upgrades specific to ore.instrument contract

  • changed minted_at to take current time instead of hard coded 0 value

• remove unused code related to allowance of instrument

• change token_id to instrument_id to maintain consistency throughout the contract

• Upgrades specific to ore.rights_registry contract

  • initialize multi index (_rights) on a higher level instead of duplicating it across functions

• Upgrades specific to ore.usage_log contract

  • initialize the logs multiindex with the constructor

[bas4r]

Looks good