Create SingleImageToPdf transformer

[mykolamelnykml]

Need to implement SingleImageToPdf transformer for convert single image to the single page pdf.

Please use img2pdf package.

It should have following params:

• inputCol
• outputCol
• resolution

Please use HasOutputCol, HasInputCol, HasResolution classes. For example:

class SingleImageToPdf(Transformer, DefaultParamsReadable, DefaultParamsWritable, HasOutputCol, HasInputCol, HasResolution):

And should use following code for transform image to pdf:

imageResolution = image.resolution
if imageResolution == 0 or imageResolution is None:
imageResolution = 300
if self.getResolution() > 0:
imageResolution = self.getResolution()

width = image.width / imageResolution * self.POINTS_PER_INCH
height = image.height / imageResolution * self.POINTS_PER_INCH

a4inpt = (img2pdf.mm_to_pt(210), img2pdf.mm_to_pt(297))
layout_fun = img2pdf.get_layout_fun(a4inpt)
pdf_bytes = img2pdf.convert(io.BytesIO(image.data), layout_fun=layout_fun)

And create good test coverage for Spark and Local pipelines.