Run should save all unsaved files

[fgrossman]

When a hitting Run to run a program, all files that have been modified and are unsaved should be saved before the program is run. This is in case a multi file program is being run, then all the changes will be saved so that the run has the latest of each file.

This is consistent with VS Code and the previous version of XRPCode.

[fgrossman]

It should pop up save dialogs as it is doing this as these may take time before the program is run. Especially when connected via bluetooth.