feat: Item validate cost, income and inventory account type.

feat: Style sales and purchases forms - 80% progress.
feat: Validate purchase-able and sell-able items in invoices and bills.
feat: Fix bugs in inventory FIFO/LIFO cost methods.

client/src/containers/Sales/Invoice/InvoiceFormFooter.js

@@ -9,7 +9,7 @@ export default function EstimateFormFooter({
   invoice,
 }) {
   return (
-    <div className={'estimate-form__floating-footer'}>
+    <div className={'form__floating-footer'}>
       <Button
         disabled={isSubmitting}
         intent={Intent.PRIMARY}