Consolidate getdata and putdata tests

[Yay295]

Moved all of the getdata and putdata tests to the same file (because test_getdata_putdata doesn't fit in either individual file), and parametrized two tests.

[radarhere]

test_image_getdata_putdata.py seems like a mouthful. How about just test_image_data.py?

[Yay295]

sure

[radarhere]

Moved all of the getdata and putdata tests to the same file (because test_getdata_putdata doesn't fit in either individual file)

Sorry, I've just realised what this meant. In main, we currently have test_image_getdata.py and test_image_putdata.py, and here you've merged them together into a single file because you'd like to find a new home for a test from test_image.py / #7209, and you don't think a roundtrip test belongs in either file.

I think test_image_putdata.py already has roundtrip tests, using both getdata() and putdata().

Pillow/Tests/test_image_putdata.py

Lines 60 to 68 in c250a44

	@pytest.mark.parametrize("mode", ("I", "I;16", "I;16L", "I;16B"))
	def test_mode_i(mode: str) -> None:
	src = hopper("L")
	data = list(src.getdata())
	im = Image.new(mode, src.size, 0)
	im.putdata(data, 2, 256)
	target = [2 * elt + 256 for elt in data]
	assert list(im.getdata()) == target

[Yay295]

I'd say those should be in the combined file for the same reason. Though I suppose I shouldn't have added putdata to those function names.

[Yay295]

Cleaned up the tests a bit more.