Saving new sketch saves to temporary folder

[per1234]

Describe the bug
File > Save saves new sketches to the temporary folder silently. The user will have trouble finding it later and the contents of the temporary folder may be subject to deletion.

To Reproduce
Steps to reproduce the behavior:

1. File > New
2. File > Save

Expected behavior
File > Save on a new sketch should open the "Save as..." dialog. This is how the Java IDE works.

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: Windows 10
• Version: 0.1.4
  Date: 2021-02-10T12:24:17.658Z
  CLI Version: 0.15.2 alpha [0d4cb150]

[federicobond]

This behavior has caused some lost work for me when I accidentally closed a temporary sketch that I thought I was saving. Do you accept pull requests addressing it?

[per1234]

Pull requests are welcome. Thanks!