consider additional functions for HyperdriveInterface

[wakamex]

things included in HyperdriveInterface:

• functions users call when writing a bot Policy (.fixed_rate, .spot_price etc.)
• functions to actually execute trades (.open_long, .close_short etc.)
  • NOT meant to be used inside the bot Policy
  • useful for users to create arbitrary behavior
• other stuff?

possible additional items to include:

• anything in the rust SDK should be in here, I believe
• other helper functions used for bot-building or arbitrary bot manipulation
• smart contract preview calls, to test out a trade before committing to it

[wakamex]

versions of these functions that we can call with arbitrary inputs: calc_apr https://github.com/delvtech/elf-simulations/pull/1000#discussion_r1362962802 calc_spot_price https://github.com/delvtech/elf-simulations/pull/1000#discussion_r1362962802 calc_bond_reserves calc_k

[wakamex]

mostly implemented, and issue-tracking for rust sdk is now done in the hyperdrive repo