Drop `.txt` for new untitled files in Save As... dialog

[chrmarti]

.txt is usually not what you want:

Maybe the 'new untitled file' is marked as a text document?

[alexr00]

There was actually a specific request to add the .txt 😄 On Windows, the .txt is automatically added. On Ubuntu, it is not added. This matches what the system file dialogues on Windows and Ubuntu both do.

[chrmarti]

There are many different file extensions used with VS Code. Replicating the system dialog's behavior makes it harder to set the filename with extension in all except the .txt case.

[alexr00]

I'll think about how we can pick a better default. Currently the file dialog receives an array of extensions, and both the simple picker and the system picker just grab the first one.

[chrmarti]

You could just drop the extension (or include it in the selection, but dropping seems preferable to me).

[alexr00]

To verify, enable the simple file picker with "files.simpleDialog.enable": true then use it to save an untitled file. Verify that .txt is not post-pended to the file name.