That's already possible. Easy.
What do you mean by the word "already"?
Even the original design of Borland's VCL and thereby the LCL of Lazarus was originally designed so separate user-interface from business (database) logic.
It s merely the fact that Borland designers did not ENFORCE that, that we still have the distinction between the VB trained screen-drawers guild and professionals.
And it is easy.. I simply can not respect PROGRAMMERS that only look at DESIGN. Designers can't program, programmers can usually not design.
In the case of Delphi and Lazarus programmers (that population is rather unbalanced between computer scientists and screen drawers with nothing in between) why don't you simply have a look at everything that's already there? BtBtn, panels, borders, forms, in general EVERYTHING you need to have a modern look.
You're lazy, y'all....
Sorry, but THAT is the case.