Allow non-UTF-8 bytes in Address::create_with_seed

[kevinheavey]

Rehashing what I wrote in this draft PR that shows what would change in solana-sdk:

The with_seed functions (eg Address::create_with_seed) and WithSeed instruction variants (eg SystemInstruction::CreateAccountWithSeed) all expect &str or String. But they don't do anything that requires UTF-8, and they just convert these values back to bytes.

Two reasons this is bad:

1. Cycles are wasted on UTF-8 validation.
2. It would be nice to use arbitrary bytes (such as an Address) as a seed. Not being able to do this causes people to do inefficient things to comply with UTF-8.

In Agave there would be some small changes to system_processor.rs and vote_processor.rs. Firedancer would need to remove its UTF-8 validation in the relevant places.

[deanmlittle]

based tbh, and nothing would break.

[kevinheavey]

SIMD here #390

[t-nelson]

so to elaborate an alternative route, as teased in https://x.com/trentdotsol/status/1983729288429105237

imagine a wrapper instruction whose sole purpose it is to perform the *WithSeed "sigverify" and invoke_signed() further instructions in its payload

SystemInstruction::CreateAccountWithSeed -> SystemInstruction::InvokeSignedWithSeed(SystemInstruction::CreateAccount)
VoteInstruction::AuthorizeWithSeed -> SystemInstruction::InvokeSignedWithSeed(VoteInstruction::Authorize)
...

accidentally burnt some tokens by assigning a *WithSeed wallet as authority? now they're accessible with SystemInstruction::InvokeSignedWithSeed(SplTokenInstruction::Authorize)

we can relax the seed constraints to [u8; 32] in the new ix and just deprecate all the old instructions

instruction probably looks something like...

// Accounts
//  0. WithSeed base 0
//  ...
//  B. WithSeed base N. B = self.with_seed_args.len() - 1
//  B+1. self.instructions[0] account 0
//  B+1+X. self.instructions[0] account N. X = self.instructions[0].num_accounts - 1
//  ...
InvokeSignedWithSeed {
    with_seed_args: [
        {
            base: Option<Address>,
            seed: [u8; 32],
        },
        ...
    ],
    instructions: [
        {
            num_accounts: usize,
            data: [u8],
        },
        ...
    ],
}

so first B account indexes map 1:1 with with_seed_args, potentially matching acting as base if with_seed_args.base is None. then for each instruction we slice out the corresponding num_accounts accounts. total account_indexes MUST be self.seeds.len() + self.instructions.iter().map(|i| i.num_accounts).sum()

save additional CUs by reusing WithSeed sigverify results