Store Debug view layout settings(column widths, etc.)

Column widths of the various debug views ("Breakpoints", "Locals and Expressions", "Stack") are not kept and restored between sessions or after restart.
The same goes for the splitter of the "Locals and Expressions" view, which always splits the available space into two equal parts.

It is a rather time-consuming to manually restore them every time the Qt Creator is restarted or after a session switch.