Build Krita with libheif in all supported platforms

libheif requires the following changes:

• Make all libraries use the common HEIF prefix
• Build libheif examples, so that we can test if the library is properly built
• Add nasm for Windows x86, drop yasm
• Add libpng and libjpeg-turbo as dependencies to libheif
• Isolate macOS build from /usr/local libraries
  • (A reason why libheif doesn't work well under macOS.)
• Fix conditional SSE4.1 support in libde265
  • See https://github.com/strukturag/libde265/blob/19db0e8f5809525a1fb7fb3f57ca59461e7186cd/libde265/x86/sse.cc#L37-L103
• Skip 10-bit and 12-bit builds on Windows x86