Add currency and exchange rate with Frankfurter per expense

messages/en-US.json

@@ -138,6 +138,10 @@
         "label": "Income date",
         "description": "Enter the date the income was received."
       },
+      "currencyField": {
+        "label": "Currency of income",
+        "description": "The currency in which the income was received."
+      },
       "categoryFieldDescription": "Select the income category.",
       "paidByField": {
         "label": "Received by",
@@ -162,6 +166,10 @@
         "label": "Expense date",
         "description": "Enter the date the expense was paid."
       },
+      "currencyField": {
+        "label": "Currency of expense",
+        "description": "The currency in which the expense was paid."
+      },
       "categoryFieldDescription": "Select the expense category.",
       "paidByField": {
         "label": "Paid by",
@@ -186,6 +194,27 @@
     "amountField": {
       "label": "Amount"
     },
+    "conversionUnavailable": "To set a different currency per expense and convert amounts, select a non-custom currency for the group.",
+    "originalAmountField": {
+      "label": "Amount to convert"
+    },
+    "conversionRateField": {
+      "useApi": "Use rates from Frankfurter",
+      "useCustom": "Use custom rate",
+      "label": "Exchange rate"
+    },
+    "conversionRateState": {
+      "loading": "Getting exchange rates…",
+      "success": "Obtained rates:",
+      "error": "Oops, we could not get the most recent rates.",
+      "staleRate": "Using rate:",
+      "noRate": "Enter a custom rate below.",
+      "currencyNotFound": "Oops, Frankfurter does not have the rate for this currency at this day.",
+      "noDate": "Enter the expense date to get a conversion rate.",
+      "dateMismatch": "Rates from date: {date}",
+      "refresh": "Refresh",
+      "customRate": "Using custom rate"
+    },
     "isReimbursementField": {
       "label": "This is a reimbursement"
     },
@@ -327,6 +356,7 @@
     "amountRequired": "You must enter an amount.",
     "amountNotZero": "The amount must not be zero.",
     "amountTenMillion": "The amount must be lower than 10,000,000.",
+    "ratePositive": "The rate must be strictly greater than zero.",
     "paidByRequired": "You must select a participant.",
     "paidForMin1": "The expense must be paid for at least one participant.",
     "noZeroShares": "All shares must be higher than 0.",