The construct gui is not understandable from the beginning

[uriyay]

1. The hex text editor in data_types.py is being updated for every change in the data.
   But I didn't want that, because the data will be rebuild every time.
   But actually now that I changed the construct editor to use a dialog a change is less frequent.
   So, in sum - the "apply" button should be removed.
2. A floating window is not very convenient, it should be docked to the hex view.
3. The data types and the construct editor should be separated.
4. Thinking about multiple construct windows so the data can be presented in many ways at once.