d3-transform: use load(<module>).document() to get topic

The previous method of using

  load('svg/transform').expression('d3.svg.transform')

would fail if the code changed to include import additional import
statements at the top.
d3-transform: use d3_array, and remove superfluous calls

use d3_array rather than redefining it. Also, don't cast argument lists
to an array when it's unnecessary.