[Proposal] Add options to control app window

[FluorescentHallucinogen]

App windows are used to display PWAs on desktop and other big screen devices like TVs, tablets, phablets, foldable devices, etc.

E.g. at this moment Desktop PWAs lack basic abilities that every desktop platform has like setting an initial desired window size, minimum and maximum window size, and so on. So I propose to add the following members to web app manifest spec to close the capabilities gap with native:

• width Integer (optional) — Window's width in pixels.
• height Integer (optional) — Window's height in pixels.
• x Integer (optional) — Window's left offset from screen.
• y Integer (optional) — Window's top offset from screen.
• minWidth Integer (optional) — Window's minimum width.
• minHeight Integer (optional) — Window's minimum height.
• maxWidth Integer (optional) — Window's maximum width.
• maxHeight Integer (optional) — Window's maximum height.
• resizable Boolean (optional) — Whether window is resizable. Default is true.
• movable Boolean (optional) — Whether window is movable. Default is true.
• minimizable Boolean (optional) — Whether window is minimizable. Default is true.
• maximizable Boolean (optional) — Whether window is maximizable. Default is true.
• closable Boolean (optional) — Whether window is closable. Default is true.
• focusable Boolean (optional) — Whether the window can be focused. Default is true.
• fullscreenable Boolean (optional) — Whether the window can be put into fullscreen mode. Default is true.
• alwaysOnTop Boolean (optional) — Whether the window should always stay on top of other windows. Default is false.

[aarongustafson]

Thank you for your interest in this space! I highly recommend getting involved in one or more of the following:

• Screen Enumeration API
• Window Placement API
• Window Segments API