Save import settings to <sheet> automatically (ORG-7725)
This way, if user saves template(OTW), or analysis template (OGW, OPJ), the import setting is saved as well.
If any modifications are done to import settings in any file import dialog (such as impasc, impcsv etc), the changes are automatically saved as a theme (theme named <sheet>) into the worksheet. This allows for easy set up of worksheet as template for future use with similar file. User does not have to remember to manually save the settings as theme to worksheet.