…web-io#1246

…on the string length before choosing which format to go for

 - this approach allows 'var()' in a styleOMValue as it's only a problem when combined with a shorthand property
 - before this change background:black; was getting expaned to 10 OM properties as follows:

'style': {
    'background-color': 'black',
    'background-image': false,
    'background-position-x': false,
    'background-position-y': false,
    'background-size': false,
    'background-repeat-x': false,
    'background-repeat-y': false,
    'background-attachment': false,
    'background-origin': false,
    'background-clip': false
}

Use neater object destructuring

Co-authored-by: Justin Halsall <Juice10@users.noreply.github.com>

prefer waitForRAF

Co-authored-by: Justin Halsall <Juice10@users.noreply.github.com>

frontload comment explaining what's going on here in terms of the 'var(' string check

Co-authored-by: Justin Halsall <Juice10@users.noreply.github.com>

Co-authored-by: Justin Halsall <Juice10@users.noreply.github.com>