improve spoof-css

[piquark6046]

In jQuery, height() and width() methods use Element.prototype.getBoundingClientRect to calculate size of an element.
However, AdGuard's spoof-css scriptlet does not mock completely the property.

Screenshot

[AdamWr]

As far as I understand, the problem occurs when 2 (or more) spoof-css scriptlets are used, for example:

example.org#%#//scriptlet('spoof-css', 'h1', 'width', '1000')
example.org#%#//scriptlet('spoof-css', 'h1', 'height', '2000')

and it looks like that the last one override/changes value set in previous scriptlet.