Add CLI features to configure screen streaming

[waydabber]

Screen streaming configuration should be available using CLI.

[waydabber]

Start streaming from screen MyDisplay to screen MyDisplay2 (you can use any of the usual target specifiers):

betterdisplaycli set -namelike=MyDisplay -stream=on -targetnamelike=MyDisplay2

Turn stream off of MyDisplay:

betterdisplaycli set -namelike=MyDisplay -stream=off

Configure various settings:

betterdisplaycli set -namelike=MyDisplay -stream -rotateby=90 -zoom=80% -flipHorizontal=on -verticalLocation=bottom

Available options:

freeAspect
directPixelMapping
rotateBy
flipHorizontal
flipVertical
horizontalLocation
verticalLocation
cursorShown
streamUnderscan
zoom
partial
partialOriginX
partialOriginY
partialWidth
partialHeight
resume