Fixes for mode=preserve (#39343)

* Fixes for mode=preserve

* Document mode=preserve for template and copy
* Make mode=preserve work with remote_src for copy
* Make mode=preserve work for template
* Integration tests for copy & template mode=preserve

Fixes #39279

* Changed mode option in win_copy to hidden option as it doesn't reflect copy mode

lib/ansible/modules/files/template.py

@@ -95,6 +95,17 @@ options:
     type: bool
     default: 'no'
     version_added: "2.4"
+  mode:
+    description:
+      - "Mode the file or directory should be. For those used to I(/usr/bin/chmod) remember that
+        modes are actually octal numbers.  You must either specify the leading zero so that
+        Ansible's YAML parser knows it is an octal number (like C(0644) or C(01777)) or quote it
+        (like C('644') or C('0644') so Ansible receives a string and can do its own conversion from
+        string into number.  Giving Ansible a number without following one of these rules will end
+        up with a decimal number which will have unexpected results.  As of version 1.8, the mode
+        may be specified as a symbolic mode (for example, C(u+rwx) or C(u=rw,g=r,o=r)).  As of
+        version 2.6, the mode may also be the special string C(preserve).  C(preserve) means that
+        the file will be given the same permissions as the source file."
 notes:
   - For Windows you can use M(win_template) which uses '\\r\\n' as C(newline_sequence).
   - Including a string that uses a date in the template will result in the template being marked 'changed' each time