…tHandle

Converts the sandbox tests hand-rolled calls whose methods exist on the
handle: propose_update (deposit now computed by the interface),
vote_update, vote_add_domains, vote_new_parameters, vote_cancel_keygen,
vote_cancel_resharing, vote_update_foreign_chain_providers,
register_foreign_chain_support, verify_tee, and
verify_foreign_transaction. Async fan-outs go through
execute_async_handle_calls, an AsyncSandboxCaller-backed twin of
execute_async_transactions.

Kept raw: deliberately malformed or under-deposited wire tests, the
legacy V1 sign shape, gas-measurement votes with tight attachments, and
methods without a handle equivalent (init*, respond*, vote_pk,
vote_reshared, vote_code_hash, keygen/reshare instances).