Issue 2379: Make it possible to select text in posts. (#2472)

* Set TextIsSelectable on the corresponding view holders and remove a longpress listener to let Android select text.

* Revert changes, and make selectable text only in detailed status.

Remove long press listener to copy to clipboard (as it interferes with natural text selection on Android).

* Remove unused string (copy_to_clipboard_success) from all translations.

Co-authored-by: Martin Marconcini <martin.marconcini.rodriguez@nl.abnamro.com>

app/src/main/res/values-sa/strings.xml

@@ -317,7 +317,6 @@
     <string name="download_fonts">प्राक्तु भावचिह्नसमूहोऽयमवारोप्यः</string>
     <string name="system_default">प्रणाल्यां पूर्वनिविष्टम्</string>
     <string name="emoji_style">भावचिह्नशैली</string>
-    <string name="copy_to_clipboard_success">अंशफलकेऽनुसृतम्</string>
     <string name="error_no_custom_emojis">भवदीयं विशिष्टस्थलं %s स्वीयानुकूलभावचिह्नरहितं वर्तते</string>
     <string name="action_compose_shortcut">लिख्यताम्</string>
     <string name="send_post_notification_saved_content">दौत्यप्रतिलिपिस्तत्र विकर्षेसु रक्षिता</string>