PP-11788 Products: PaymentCreationException

Following review change the following:
- Use curly quotation marks in newly added text.
- Change invalid reference and amount messages to avoid use of negative contractions.
- Amount must be in pence for prefilled payment links.
- Update Welsh translations for changed text.

locales/cy.json

@@ -23,8 +23,8 @@
   "paymentLinkError": {
     "title": "Digwyddodd gwall:",
     "invalidReference": "Rhif mae’n rhaid i fod yn 255 nod neu lai. Ni allwch ddefnyddio unrhyw rai o’r nodau canlynol < > ; : ` ( ) \" ' = &#124; \",\" ~ [ ] .",
-    "invalidAmount": "Cofnodwch swm mewn punnoedd a cheiniogau gan ddefnyddio digidau a phwynt degol, fel 123.45 neu 156.00 a yn £100,000 neu lai.",
-    "linkProblem": "Mae problem gyda'r ddolen sydd wedi cael ei hanfon atoch i'w defnyddio i dalu. Cysylltwch â'r gwasanaeth rydych yn ceisio gwneud taliad iddo."
+    "invalidAmount": "Cofnodwch swm mewn ceiniogau. Er enghraifft “2000”.",
+    "linkProblem": "Mae problem gyda’r ddolen sydd wedi cael ei hanfon atoch i’w defnyddio i dalu. Cysylltwch â’r gwasanaeth rydych chi’n ceisio gwneud taliad iddo."
   },
   "404Page": {
     "title": "Ni chanfuwyd y dudalen",

locales/en.json

@@ -22,9 +22,9 @@
   },
   "paymentLinkError": {
     "title": "An error occurred:",
-    "invalidReference": "Reference must be 255 characters or fewer. You can’t use any of the following characters < > ; : ` ( ) \" ' = | \",\" ~ [ ]",
-    "invalidAmount": "Amount must be in pounds and pence using digits and a decimal point, like 123.45 or 156.00 and £100,000 or less.",
-    "linkProblem": "There is a problem with the link you have been sent to use to pay. Please contact the service you're trying to make a payment to."
+    "invalidReference": "Reference must be 255 characters or fewer. You cannot use any of the following characters < > ; : ` ( ) \" ' = | \",\" ~ [ ]",
+    "invalidAmount": "Enter an amount in pence. For example “2000”.",
+    "linkProblem": "There is a problem with the link you have been sent to use to pay. Please contact the service you are trying to make a payment to."
   },
   "404Page": {
     "title": "Page not found",