float input, use toLocaleString instead of toString

toLocalString never uses exponential notation, so it works
better with our current system:
- with the acceptValue regex, exponential notation is rejected
so the user can't edit the field at all anymore
- even if exponential notation was accepted, switching automatically from
plain to exponential or vice versa is hard to understand and predict because
the input changes a lot, eg 10000000000000 -> 1e22
- even if it could be implemented, cursor position preservation becomes
even more complex with exponential notation. Note: even with toLocaleString,
the cursor may jump with more than 15 digits when precision forces a change in
digits

src/components/react-hook-form/numbers/float-input.js

@@ -32,7 +32,18 @@ const FloatInput = (props) => {
         if (tmp.endsWith('.') || tmp.endsWith('0')) {
             return tmp;
         }
-        return parseFloat(tmp) || null;
+
+        // toLocaleString never uses exponential notation unlike toString.
+        // Avoiding exponential notation makes in place normalizing of numbers
+        // after each keystroke less intrusive. Note: with 16+ digits, rounding
+        // due to precision still causes the cursor to jump at the end...
+        // This should be fixable with manual cursor handling if we need it.
+        return (
+            parseFloat(tmp).toLocaleString('en-US', {
+                maximumFractionDigits: 20,
+                useGrouping: false,
+            }) || null
+        );
     };
 
     return (