Improve auto sizing & layout for main window and subwindows

[kvesik]

These issues came up in discussion at 20240516 meeting, after I adjusted the sign level menu in issue #309 .

• default overall window size is 1800x1040 - this is still somewhat wide for some users
• make entire window a bit narrower still-- can this depend on the user's screen resolution?
• can the subwindow configuration make a reference to the overall (main window) size?
• Grace says: "when i maximize a subwindow and then hit restore default view, it doesn't un-maximize the window"
• Stanley says: "same issue. also for dual monitor, the restore default view forces the window back to the primary monitor, even when i've been using slpaa on my secondary"

May need some more discussion / specification before the issue can actually be tackled.