[Feature request] periodically check if open files were touched from outside

[i-make-robots]

In Windows 10, most IDEs and text editors will notice that a file was changed by some other application. Arduino is a notable exception.

Test case:

• use ide to load file from disk
• touch the file from some other application.

What's expected:

• "Warning: File has changed on disk. Reload ? [yes]/[no]"
• if yes, reload file without losing other files (unsaved work in other tabs)

What happens:

• nothing.

Possible method:

• repeating 5s timer that watches file last touched time.

Thank you, stay awesome!

[per1234]

I'm going to close this as a duplicate of #4551

Note that there is an existing pull request that will do what you are requesting, except without the prompt:
#6074

Also note that the Arduino IDE does already update according to outside edits if you have File > Preferences > Use External Editor checked. The only limitation is this makes the Arduino IDE's editor window read-only, so you can't edit the sketch using both the external editor and the Arduino IDE.