Opening example sketch does not check the .development file flag

[KurtE]

Describe the problem

If you open an example sketch and you have marked the library as being in development.

As described in: https://arduino.github.io/arduino-cli/0.21/library-specification/#development-flag-file

The file is still opened up in the temporary directory not shown as within the library.

On IDE1, the example is opened, I can edit it and then do a save and the example is updated in place.

To reproduce

mark a library as in development, by creating the .development file,
And open an example sketch within that folder.

Expected behavior

Same as IDE1

Arduino IDE version

running 0401 nightly

Operating system

Windows

Operating system version

10

Additional context

I mentioned this in comment to #925

@per1234 mentioned that the CLI does not even pickup the presences of this file:
https://arduino.github.io/arduino-cli/0.21/rpc/commands/#library

Additional reports

• Opening example sketch does not check the .development file flag #936 (comment)
• Opening example sketch does not check the .development file flag #936 (comment)

Issue checklist

• I searched for previous reports in the issue tracker
• I verified the problem still occurs when using the latest nightly build
• My report contains all necessary details