Revise RequestError, add specific alternate enums

[dhardy]

• Tested on all platforms changed
• Added an entry to the changelog module if knowledge of this change could be valuable to users
• Updated documentation to reflect any user-facing changes, including notes of platform-specific behavior
• Created or updated an example program if it would help users understand this functionality

This is the result of reviewing all existing RequestError failures / usages.

CC @Murmele. See also: #4706, #4399.

[dhardy]

Rebased, adding a new internal ResolveStateError type to winit-wayland/window/common.