[Feature Request] Don't override existing files

[aaronshenhao]

Is your feature request related to a problem? Please describe. I noticed that the software actually overwrites files without warning, and the overwritten files are deleted permanently. This is really unexpected, and led to the loss of a file I made previously.

Describe the solution you'd like If the file exists, prompt the user on whether they want to override the original file, or rename the new file. If the user chooses to override the original file, move the original file to the recycle bin.

Additional context This is for the Windows app (hence the recycle bin).