fix(dashboard,medusa): Fixes to Customer and Customer Groups domains (#7081)

**What**
- Cleanup of domains
- Adds toasts
- Adds delete customer hook
- Fixes validation of create and update customer endpoints.

packages/admin-next/dashboard/src/components/table/table-cells/common/text-cell/text-cell.tsx

@@ -1,3 +1,5 @@
+import { PlaceholderCell } from "../placeholder-cell"
+
 type CellProps = {
   text?: string | number
 }
@@ -7,6 +9,10 @@ type HeaderProps = {
 }
 
 export const TextCell = ({ text }: CellProps) => {
+  if (!text) {
+    return <PlaceholderCell />
+  }
+
   return (
     <div className="flex h-full w-full items-center gap-x-3 overflow-hidden">
       <span className="truncate">{text}</span>
@@ -16,8 +22,8 @@ export const TextCell = ({ text }: CellProps) => {
 
 export const TextHeader = ({ text }: HeaderProps) => {
   return (
-    <div className=" flex h-full w-full items-center">
-      <span>{text}</span>
+    <div className="flex h-full w-full items-center">
+      <span className="truncate">{text}</span>
     </div>
   )
 }

packages/admin-next/dashboard/src/components/table/table-cells/customer/account-cell/account-cell.tsx

@@ -9,7 +9,9 @@ export const AccountCell = ({ hasAccount }: AccountCellProps) => {
   const { t } = useTranslation()
 
   const color = hasAccount ? "green" : ("orange" as const)
-  const text = hasAccount ? t("customers.registered") : t("customers.guest")
+  const text = hasAccount
+    ? t("customers.fields.registered")
+    : t("customers.fields.guest")
 
   return <StatusCell color={color}>{text}</StatusCell>
 }

packages/admin-next/dashboard/src/components/table/table-cells/customer/first-seen-cell/first-seen-cell.tsx

@@ -1,11 +1,16 @@
 import { useTranslation } from "react-i18next"
 import { DateCell } from "../../common/date-cell"
+import { PlaceholderCell } from "../../common/placeholder-cell"
 
 type FirstSeenCellProps = {
-  createdAt: Date
+  createdAt?: Date | string | null
 }
 
 export const FirstSeenCell = ({ createdAt }: FirstSeenCellProps) => {
+  if (!createdAt) {
+    return <PlaceholderCell />
+  }
+
   return <DateCell date={createdAt} />
 }
 
@@ -14,7 +19,7 @@ export const FirstSeenHeader = () => {
 
   return (
     <div className="flex h-full w-full items-center">
-      <span className="truncate">{t("customers.firstSeen")}</span>
+      <span className="truncate">{t("fields.createdAt")}</span>
     </div>
   )
 }