Add max supply and current supply to budget object

[abitmore]

Fixes #2303.

New fields:

bitshares-core/libraries/chain/include/graphene/chain/budget_record_object.hpp

Lines 59 to 63 in af9cafe

	/// Maximum supply
	share_type max_supply;
	/// Current supply
	share_type current_supply;

All fields:

bitshares-core/libraries/chain/include/graphene/chain/budget_record_object.hpp

Lines 30 to 64 in af9cafe

	struct budget_record
	{
	uint64_t time_since_last_budget = 0;
	/// Sources of budget
	///@{
	share_type from_initial_reserve = 0;
	share_type from_accumulated_fees = 0;
	share_type from_unused_witness_budget = 0;
	///@}
	/// Witness budget requested by the committee
	share_type requested_witness_budget = 0;
	/// Funds that can be released from reserve at maximum rate
	share_type total_budget = 0;
	/// Sinks of budget, should sum up to total_budget
	///@{
	share_type witness_budget = 0;
	share_type worker_budget = 0;
	///@}
	/// Unused budget
	share_type leftover_worker_funds = 0;
	/// Change in supply due to budget operations
	share_type supply_delta = 0;
	/// Maximum supply
	share_type max_supply;
	/// Current supply
	share_type current_supply;
	};