Support for invertAffineTransform

[FromDarkHell]

There's no support for invertAffineTransform in the library currently, src/imgproc/imgproc.dart just needs:

void invertAffineTransform(cv.InputArray M, cv.OutputArray iM) {
  using((arena) {
    bindings.InvertAffineTransform(M.ptr, iM.ptr);
  });
}

[rainyl]

👌,will add soon.

BTW, would you mind to provide a test case?

[rainyl]

Added in v0.6.6, I am going to close this issue.