Convert ZSTD to ZSTD_Seekable about wombattools

[pjrinaldi]

got imager working with zstd seekable. need to figure out what to do with the wfi metadata and where to put it. it can't go at the end of the file since the seek table goes there for the zstd_seekable. right now i have it in a separate binary .md file.

working on getting wombatmount working through fuse. if i can't figure it out, i may need to switch from zstd to something else such as xz which is seekable or simply zip which is also seekable.

[pjrinaldi]

this is still slower than using a walafus read only zstd compressed filesystem to store the raw image and the log and the info file. so i'm switching over to this method and current wombatimager is working, going to start working on wombatread, wombatinfo, wombatlog, wombatverify, and wombatrestore. might do a fuse, but it isn't necessary due to the other helper functions. wombatforensics currently parses the walafus image format, and i'll move that code into the WFI imgtype format and remove the walafus imgtype