Unify selecting a sequence region to use

There are several places throughout UGENE where a user can select either "Whole sequence" or a "Selected" region or a custom region.

In each place the functionality is implemented separately and differs a lot in GUI. Also because of this in some places the behavior differs from other places, e.g. in the "Create DNA Fragment" dialog (see cloning) the "Selected" item is not disabled when a sequence region hasn't been selecting before opening the dialog.

Couldn't it be implemented in one separate common widget?

The following dialogs has this functionality:

• Analyze with Query Schema
• Find Repeats
• Find Tandems
• Smith-Waterman Search
• Weight Matrix Search
• SITECON Search
• Create DNA Fragment
• Primer 3
• ORF