Seperate page widgets

[oluwandabira]

Currently most widgets live in Window.inputs or Window.outputs and this has gotten quite cumbersome ( Window.handleinputs is also very long as a result).
This need to be improved.

[oluwandabira]

I propose changing the window to hold a map[string]layout.Widget for all pages.

• Pages themselves should be a structure that has a method (something along the lines of a page.Construct) that takes pointers to the window data it needs and returns a layout.Widget that lays out the page when called.
• The construction method should only take the window data used.
• For widget data that can change the page should construct the widget within the layout function as the window will not communicate data changes to the pages.
• Dialogs will remain the same (a single dialog variable) but we expand the number of pages.
• There would pretty much only be about 3 dialogs (confirm, info, enter password) but other more specific dialogs can also be included.
• If a dialog needs to call another dialog it should be a page.