Display numbers in account header using shortNumberFormat for consistency (#7723)

app/javascript/mastodon/utils/numbers.js

@@ -0,0 +1,10 @@
+import React, { Fragment } from 'react';
+import { FormattedNumber } from 'react-intl';
+
+export const shortNumberFormat = number => {
+  if (number < 1000) {
+    return <FormattedNumber value={number} />;
+  } else {
+    return <Fragment><FormattedNumber value={number / 1000} maximumFractionDigits={1} />K</Fragment>;
+  }
+};