fix: add A → a replacement in dateFns localeParse for use12Hours support

When use12Hours is enabled, rc-picker internally injects uppercase A
(moment.js AM/PM token) into the format string. date-fns uses lowercase
a for AM/PM, so passing A through causes:

  RangeError: Format string contains an unescaped latin alphabet character `A`

localeParse already converts other moment tokens (Y→y, D→d, etc.) but
was missing A→a. This adds it.

Fixes #964

Author: daedalus28

src/generate/dateFns.ts

@@ -41,7 +41,8 @@ const localeParse = (format: string) => {
     .replace(/D/g, 'd')
     .replace(/gggg/, 'yyyy')
     .replace(/g/g, 'G')
-    .replace(/([Ww])o/g, 'wo');
+    .replace(/([Ww])o/g, 'wo')
+    .replace(/A/g, 'a');
 };
 
 const parse = (text: string, format: string, locale: string) => {