accounts-db: snapshot utils + hash verification

[0xNineteen]

build.zig

• make it easy to add new executables with all the required modules

src/cmd/snapshot_utils.zig

• snapshot utils for:
  • dumping the accounts_db.bincode from the full bank metadata (the full bank metadata is quite large, and we only need the accounts_db fields to correctly parse the append_vecs)
  • dump accounts found in append vec into a .csv format (TODO: current approach contains duplicate accounts + not most recent -- will likely need to merge logic with account hash verification which does this sorting)

src/cmd/snapshot_verify.zig

• logic for verifying the account hash of a snapshot matches the metadata
• TODO: is currently slow relative to rust-impl -- should be able to optimize it

src/common/merkle_tree.zig

• simple merkle tree hash calculation

src/core/account.zig

• logic for hashing account