Replace redwood flash with toaster

https://community.redwoodjs.com/t/redwood-flash-is-being-replaced-with-react-hot-toast-how-to-update-your-project-v0-27-0/1921
Resolves #326.

app/web/src/components/AdminParts/AdminParts.js

@@ -1,4 +1,5 @@
-import { useMutation, useFlash } from '@redwoodjs/web'
+import { useMutation } from '@redwoodjs/web'
+import { toast } from '@redwoodjs/web/toast'
 import { Link, routes } from '@redwoodjs/router'
 
 import { QUERY } from 'src/components/AdminPartsCell'
@@ -21,10 +22,6 @@ const truncate = (text) => {
   return output
 }
 
-const jsonTruncate = (obj) => {
-  return truncate(JSON.stringify(obj, null, 2))
-}
-
 const timeTag = (datetime) => {
   return (
     <time dateTime={datetime} title={datetime}>
@@ -38,10 +35,9 @@ const checkboxInputTag = (checked) => {
 }
 
 const AdminParts = ({ parts }) => {
-  const { addMessage } = useFlash()
   const [deletePart] = useMutation(DELETE_PART_MUTATION, {
     onCompleted: () => {
-      addMessage('Part deleted.', { classes: 'rw-flash-success' })
+      toast.success('Part deleted.')
     },
     // This refetches the query on the list page. Read more about other ways to
     // update the cache over here: