replace solana_sdk::pubkey with solana_pubkey in rpc

[kevinheavey]

Problem

This crate uses solana_sdk in many places. It will take multiple PRs to replace it everywhere

Summary of Changes

Find and replace solana_sdk::pubkey with solana_pubkey

[mergify]

If this PR represents a change to the public RPC API:

1. Make sure it includes a complementary update to rpc-client/ (example)
2. Open a follow-up PR to update the JavaScript client @solana/web3.js (example)

Thank you for keeping the RPC clients in sync with the server API @kevinheavey.

[LucasSte]

Looks good to me. Perhaps @steviez or @bw-solana, who are more familiar with RPC, may want to have a look as well.

[bw-solana]

LGTM - thanks for cleaning this up!

[bw-solana]

For posterity, solana_sdk::pubkey has been deprecated since v2.1.0, but it is still used many places as a tunnel to access these includes from solana_pubkey:

#[cfg(feature = "full")]
pub use solana_pubkey::new_rand;
#[cfg(target_os = "solana")]
pub use solana_pubkey::syscalls;
pub use solana_pubkey::{
    bytes_are_curve_point, ParsePubkeyError, Pubkey, PubkeyError, MAX_SEEDS, MAX_SEED_LEN,
    PUBKEY_BYTES,
};

If we use solana_pubkey directly, we can remove this

[steviez]

LGTM

but it is still used many places as a tunnel to access these includes from solana_pubkey:
...
If we use solana_pubkey directly, we can remove this

Agreed and I imagine this is the desired endgame for when we fully deprecate solana_sdk::pubkey (I'm guessing whenever we launch a 3.0)