Assert stake item stage in response handler

[Overseven]

Function try_handle_stake_response can be called for stake_item with action_stage != StakeActionStage::Execute.
We should add stake item stage assertion.

warden-yield/cosmwasm/contracts/yield-ward/src/execute/response_stake.rs

Lines 33 to 38 in db2f825

	if stake_response.status == Status::Success {
	// update stake stats
	stake_stats.pending_stake -= Uint256::from(stake_amount);
	stake_stats.lp_token_amount += Uint256::from(stake_response.lp_token_amount);
	STAKE_STATS.save(deps.storage, &token_denom, &stake_stats)?;