feat(image, layer): add bitmap mask feature

[kisvegabor]

Description of the feature or fix

Allow using an A8 bitmap mask for

• the image widget
• as a style property in which case a layer will be created and that layer will be masked

Current limitations

• In SW render transformation and mask doesn't work together
• In SW render only RGB565A8 and A8 images cannot be masked at this moment.
• The mask is always center aligned on the image. Tiling and positioning can be added later.

Test and docs is still missing. First, I would like to verify if you agree with my approach on this feature.

cc @XuNeo

Notes

• Update the Documentation if needed.
• Add Examples if relevant.
• Add Tests if applicable.
• If you added new options to lv_conf_template.h run lv_conf_internal_gen.py and update Kconfig.
• Run scripts/code-format.py (astyle needs to be installed) and follow the Code Conventions
• Mark the Pull request as Draft while you are working on the first version, and mark is as Ready when it's ready for review.
• When changes were requested, re-request review to notify the maintainers.
• Help us to review this Pull Request! Anyone can approve or request changes.

[XuNeo]

Thank you Gabor. It looks good to me.
@bjsylvia @terry0012 @FASTSHIFT Please help to review the code.

[kisvegabor]

@XuNeo I merge it now, please open an issue if feel like something is missing.