`:e` doesn’t work on Windows when using a Linux remote system

Describe the bug
When running on Windows but working against a remote that uses Linux, commands like :e file fail to work, seemingly because VSCodeVim resolves the path using the host’s directory separator (Windows, \) rather than the remote platform’s (Linux, /). And while Windows will generally cope with being given / in paths, other platforms refuse to countenance \.

To Reproduce
Steps to reproduce the behavior:

1. Use Windows.
2. Set up a remote environment that uses Linux, e.g. WSL.
3. :e /path/to/file (for some path of your own devising that exists; absolute and relative paths are all fine, and :tabe demonstrates the issue too).
4. See error notification like this:

   Unable to open 'file': Unable to read file '\path\to\file' (Error: Unable to resolve non-existing file '\path\to\file').”.

Expected behavior
The file /path/to/file should have opened.

Environment (please complete the following information):

• Extension (VsCodeVim) version: 1.14.3
• VSCode version: 1.45.1
• OS: Windows_NT x64 10.0.19041

Start by tracing the :e and :tabe command handling described in the issue, focusing on where paths are resolved for remote environments. Reproduce the Windows-to-Linux case with /path/to/file; done means both commands open existing remote files without converting / to \.