Fail when running the token-accounts-by-owner benchmark suite without supplying --mint

[steveluscher]

Problem

Forget to supply the --mint argument when running the token-accounts-by-owner benchmark?

sol@dev-luscher-dallas-1:~/src/agave/accounts-cluster-bench$ cargo run -- --identity ~/.config/solana/id.json --rpc-bench token-accounts-by-owner --rpc-bench slot --iterations 0 --url l 
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.57s
     Running `/home/sol/src/agave/target/debug/solana-accounts-cluster-bench --identity /home/sol/.config/solana/id.json --rpc-bench token-accounts-by-owner --rpc-bench slot --iterations 0 --url l`
error: The following required arguments were not provided:

USAGE:
    solana-accounts-cluster-bench --config <FILEPATH> --identity <FILE>... --iterations <NUM_ITERATIONS> --url <URL_OR_MONIKER> --mint <MINT_ADDRESS> --rpc-bench <RPC_BENCH_TYPE(S)>...

For more information try --help

Summary of Changes

Enforce that --mint is supplied when token-accounts-by-owner is set.

[steveluscher]

It's an array, because we're going to add token-accounts-by-delegate in a separate PR.

[mergify]

automerge label removed due to a CI failure