add braces around the single line condition

Made changes to constraints for chroma format and bit depth, according
to meeting notes on JVET-S0094.
Also added encoder and decoder side checks.

VUI modifications including VUI length, moving two flags from GCI to
VUI, reordering VUI variables to follow syntax elements

Constraint that no subpicture can be outside the conformance cropping
window + rewrite the conformance cropping window when extracting a
subpicture