migrate_delegation: TxDescriptor<{
    member_account: MultiAddress;
}>

Migrates delegated funds from the pool account to the member_account.

Fails unless [crate::pallet::Config::StakeAdapter] is of strategy type: [adapter::StakeStrategyType::Delegate].

This is a permission-less call and refunds any fee if claim is successful.

If the pool has migrated to delegation based staking, the staked tokens of pool members can be moved and held in their own account. See [adapter::DelegateStake]