SelectableOptionRow [nfc]: Add, to replace LanguagePickerItem.

Created by copy-pasting `LanguagePickerItem`.

In the next several commits, we'll make this into a more
general-purpose component that may be useful to represent a checkbox
or a radio button.

Then we'll switch `LanguagePickerItem`'s caller to use this
component instead, and remove `LanguagePickerItem`. We'll also use
it for the items on `UserStatusScreen`, which now incorrectly show
right-facing arrows, as though they'll navigate somewhere.

Future uses of this component (e.g., we may want it for zulip#4009) can
help refine its interface. For now, just let that process start --
and make it easier to provide a consistent look-and-feel -- by
making a reusable component.

src/common/SelectableOptionRow.js

@@ -0,0 +1,51 @@
+/* @flow strict-local */
+import React from 'react';
+import { View } from 'react-native';
+
+import { RawLabel, Touchable } from '.';
+import { BRAND_COLOR, createStyleSheet } from '../styles';
+import { IconDone } from './Icons';
+
+const styles = createStyleSheet({
+  languageWrapper: {
+    flex: 1,
+    flexDirection: 'column',
+  },
+  name: {
+    fontWeight: '300',
+    fontSize: 13,
+  },
+  listItem: {
+    flexDirection: 'row',
+    alignItems: 'center',
+    paddingTop: 12,
+    paddingBottom: 12,
+    paddingLeft: 16,
+    paddingRight: 16,
+  },
+});
+
+type Props = $ReadOnly<{|
+  locale: string,
+  name: string,
+  nativeName: string,
+  selected: boolean,
+  onValueChange: (locale: string) => void,
+|}>;
+
+// Not ready to use.
+export default function LanguagePickerItem(props: Props) {
+  const { locale, name, nativeName, selected, onValueChange } = props;
+
+  return (
+    <Touchable onPress={() => onValueChange(locale)}>
+      <View style={styles.listItem}>
+        <View style={styles.languageWrapper}>
+          <RawLabel text={nativeName} />
+          <RawLabel text={name} style={styles.name} />
+        </View>
+        <View>{selected && <IconDone size={16} color={BRAND_COLOR} />}</View>
+      </View>
+    </Touchable>
+  );
+}