Add PEF (Preffered Executable Format) support (#406)

* Initial version of PEF

* add pef test file

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Co-authored-by: paxcut <53811119+paxcut@users.noreply.github.com>

Author: domin568

README.md

@@ -131,6 +131,7 @@ Everything will immediately show up in ImHex's Content Store and gets bundled wi
 | PCK | | [`patterns/pck.hexpat`](patterns/pck.hexpat) | Minecraft Legacy Console Edition .pck file |
 | PCX | `application/x-pcx` | [`patterns/pcx.hexpat`](patterns/pcx.hexpat) | PCX Image format |
 | PE | `application/x-dosexec` `application/x-msdownload` | [`patterns/pe.hexpat`](patterns/pe.hexpat) | PE header, COFF header, Standard COFF fields and Windows Specific fields |
+| PEF | | [`patterns/pef.hexpat`](patterns/pef.hexpat) | Preffered Executable Format executable (for Mac OS 7.1.2 - Mac OS 10.4 / BeOS) |
 | PEX | | [`patterns/pex.hexpat`](patterns/pex.hexpat) | Bethesda Papyrus executable compiled script file |
 | PP | | [`patterns/selinuxpp.hexpat`](patterns/selinuxpp.pat) | SE Linux package |
 | PFS0 | | [`patterns/pfs0.hexpat`](patterns/pfs0.hexpat) | Nintendo Switch PFS0 archive (NSP files) |