Adds a very basic implementation of storage standard to facilitate FT donations, where deposit to store donation is required before ft_transfer_call is called.
Adds ft_on_transfer method to facilitate FT donations
Handles success/failure of donation & fees transfers, rolling back donation if necessary (uses next_donation_id to avoid overwrites)
Stores amounts as integers internally instead of strings, making donation storage more predictable
Introduces ephemeral DonationExternal struct to convert amount integers to strings for return values / view methods.
ft_transfer_callis called.ft_on_transfermethod to facilitate FT donationsnext_donation_idto avoid overwrites)DonationExternalstruct to convert amount integers to strings for return values / view methods.