It urgently needs an alert when replacing a existing file #1400

Prerequisites

[X] Put an X between the brackets on this line if you have done all of the following:
* Checked that your issue isn't already filed: https://github.com/icetee/remote-ftp/issues

Description

The extension will delete all the content of any existing file without any way to recover it (if not using git or manual backups) if by mistake we try to create a new file with the same name

Steps to Reproduce

1. create a file with remote-ftp on the ftp side
2. a new file is opened without any confirmation and the previous content, on both local and ftp is completely gone...

Expected behavior:
We should get an alert when creating a file and it already exists.

Actual behavior: [What actually happens]
If we try to create a file and it already exists, the extension will simply and blindly create and replaces the old file with a new blank one, on both ftp and local, literally destroying said file without any way to recover it if the user isn't actively making backups.
People can create files by mistake that already exist if they happen to be in the wrong folder by mistake for example.

Reproduces how often:
100% of the time

Versions

OSX :12.5.1
Atom : 1.60.0
Electron : 9.4.4
Chrome : 83.0.4103.122
Node : 12.14.1