runtime-genesis-ledger: added a new cli flag `--hardfork-slot`. It is the scheduled hardfork slot since last hardfork at which vesting parameter update should happen. User must also pass in a companion `--prefork-genesis-config` specifying the prefork genesis config's file path, used to provide the fork slot of the last fork. If they're both absent, no update will be applied for vesting parameters.

daemon: now when `--hardfork-handling` is set to `migrate-exit` we will enforce `slot_chain_end` & `hard_fork_genesis_slot_delta` being set in config, and the vesting parameter update would be applied when converting ledger into hardfork format.