add priority fees to all commands

[samuelvanderwaal]

Uses the following micro-lamport mappings from "level":

    match priority {
        Priority::None => 1_000,
        Priority::Low => 50_000,
        Priority::Medium => 200_000,
        Priority::High => 1_000_000,
        Priority::Max => 2_000_000,
    }

and defaults to "low". Given the low-compute nature of Nifty Asset instructions, this results in low additional fees approximately less than or equal to an additional signature cost, but which should put the instruction above the priority fee level once that comes back into play on mainnet.

A mint-batch command: https://explorer.solana.com/tx/4ENmVmLh9Eo68SXwin9YsM2qHs3nWhmD2Z44zXaW7UTyu37TnHayWZwqaiaL1v8fv2WCHRwB7eUkZXg6BLbJzoW4

Minting transactions actually go through now, although they are slow due to congestion:

Transfer command: 3ExYzQDVPRVyjbMGDgDqEP7byFLcz33yR6mVNoWanvxs4MRiWFyENPjFfVgmENzTeJV63dT4aHCGa6A1DgDLU6fC

[febo]

Great stuff!