Way to easy specify NCLX output color profile

[bigcat88]

This PR provides a way to easy specify NCLX output color profile.

Changes proposed in this pull request:

• Image write tests were disabled if libheif has lower version then 1.17.3 (libheif has some bug in 1.16.x versions, that crashes the process in some cases when NCLX writing is enabled)
• SAVE_NCLX_PROFILE changed to be True by default.
• color_primaries, transfer_characteristics, matrix_coefficients, full_range_flag - can be specified as a parameters for save operation.

This approach allow easy to encode in lossless mode:

    buf = BytesIO()
    im_rgb.save(buf, format=save_format, quality=-1, chroma=444, matrix_coefficients=0)
    helpers.assert_image_equal(im_rgb, Image.open(buf))

Also it allows like before just change nclx values in info dictionary:

    buf = BytesIO()
    im.info["nclx_profile"]["matrix_coefficients"] = 0
    im.info["nclx_profile"]["color_primaries"] = 1
    im.save(buf, format="HEIF")

The documentation has been updated with this information, in theory that's it, the problem with NCLX color profiles is solved and closed.

strukturag/libheif#995

[codecov]

Codecov Report

Merging #171 (10ae2c4) into master (365d230) will not change coverage.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff            @@
##            master      #171   +/-   ##
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  Coverage   100.00%   100.00%           
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  Files           10        10           
  Lines          907       906    -1     
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- Hits           907       906    -1     

Files	Coverage Δ
pillow_heif/heif.py	100.00% <ø> (ø)
pillow_heif/misc.py	100.00% <100.00%> (ø)
pillow_heif/options.py	100.00% <100.00%> (ø)