stdlib/os: Add options argument to copy functions

Sometimes there is a need to copy symlinks as they are. This commit adds
optional argument `options` to all copy functions in `os` module.

`options` argument is an object for easier modification in the future.

Also, bugs in `copyDir`, `copyDirWithPermissions`, `moveDir` functions
are fixed: now symlinks are copied as they are (before this commit,
they were skipped).

Note:
Inspired by https://docs.python.org/3/library/shutil.html#shutil.copy
and https://en.cppreference.com/w/cpp/filesystem/copy_options

Author: Roman Inflianskas

changelog.md

@@ -109,6 +109,13 @@ with other backends. see #9125. Use `-d:nimLegacyJsRound` for previous behavior.
 
 - Removed the optional `longestMatch` parameter of the `critbits._WithPrefix` iterators (it never worked reliably)
 
+- Added optional `options` argument to `copyFile`, `copyFileToDir`, `copyDir`,
+  `copyFileWithPermissions`, and `copyDirWithPermissions`. By default,
+  `copyFile`, `copyFileToDir`, `copyFileWithPermissions` follow the symlinks
+  (copy files symlinks point to), and `copyDir`, `copyDirWithPermissions` copy
+  symlinks as they are (instead of skipping them as it was before). Also,
+  `moveFile` and `moveDir` now always move symlinks as they are.
+
 ## Language changes
 
 - `nimscript` now handles `except Exception as e`.