Checks whether the specified purchase can be removed from a user account.
Purchases included with a plan can't be removed.

@param {Object} purchase - the purchase with which we are concerned
@return {boolean} true if the purchase can be removed, false otherwise
function isRemovable( purchase ) {
	if ( isIncludedWithPlan( purchase ) ) {
		return false;
	}

	if ( isConciergeSession( purchase ) ) {
		return false;
	}

	return (
		isJetpackPlan( purchase ) ||
		isExpiring( purchase ) ||
		isExpired( purchase ) ||
		( isDomainTransfer( purchase ) &&
			! isRefundable( purchase ) &&
			isPurchaseCancelable( purchase ) )
	);
}