[feature enhancement] change document desynchronization warnings

[djon_3V3]

Hi there.

If i open an electronics schematics without opening the project itself, i get a banner warning that documents might not sync if modified.

I think there are multiple problems with how this is done, but it is present right when opening the document. Not sure it is okay to remind me immediately that i might be doing something wrong even if i know it, and even if document is still very ok until it gets modified.

Would be like someone reminding me all the time that stairs are dangerous, even if i just pass by. Yeah, i know, you said it million times, i got it and i am not going to use them. Thanks but get a bit more conscious of context.

then 

- this message ought to only appear IF we make a modification AND propose to open the project on a click so the situation is safe.

AND/OR

- we should also get a fair warning if we try to save a modified unsynched document

OR

- documents that can trigger an unwanted amount of chaos should not be editable until you figure out a way to make that safe in every cases.

Have a great day.