Improving handling of custom control linked to log tabs

[pybride]

• Displaying correctly custom control when restoring docking layout (including floating panel on secondary monitor)
• allow each log tab to have his instance of custom control (using the new LogWindowId)
• Calling disposing when closing a log window, to also close any linked floating panel(s)

See corresponding interfaces modifications (nuget issue created unwanted changes below).

What isn't corrected: when changing active log tab, the linked floating panel don't switch. Also, the title of the floating panel is random (panelContainer1).