pytsk/libtsk add apfs support

[joachimmetz]

adding apfs support to pytsk is on hold. OSS-Fuzz is finding many issues in the libtsk apfs code that need to be addressed first:

• https://github.com/sleuthkit/sleuthkit/issues/2641
• https://github.com/sleuthkit/sleuthkit/issues/2625
• https://github.com/sleuthkit/sleuthkit/issues/2708
• https://github.com/sleuthkit/sleuthkit/issues/2707
• https://github.com/sleuthkit/sleuthkit/issues/2721