feat(handler): add par2 directory handler

[rxpha3l]

Parchive or PAR2, is a format for creating redundant data that helps detect and repair corrupted files. These archives typically accompany split-file sets (like multi-volume RAR or ZIP archives). Each PAR2 file is composed of multiple “packets.” The header starts with PAR2\x00PKT

Create PAR2 file:

par2create backup.par2 file_to_protect
While creating PAR2 backup of a file, parchive creates in the same directory multiple .par2 file. Every file that ends with .volXX+YY.par2 specifies form which block (X), how many more blocks it contains (Y).
E.g. backup.vol01+02.par2 would contain the first block + 2 more blocks etc.

Verify PAR2 file:

par2verify backup.par2

Header :

8 bytes : Magic
8 bytes : Packet length
16 bytes : MD5 hash
16 bytes : Recovery set ID
16 bytes : Recovery Type

Unblob identifies each PAR2 file in a given directory by validating the magic signature, computing the MD5 hash and validating it with the MD5 hash in the header. Since parchive is a repair tool, no extractor is specified.

[Sources]
https://docs.fileformat.com/compression/par/
https://parchive.github.io/
https://github.com/Parchive/par2cmdline/tree/master/src
https://parchive.github.io/doc/Parity%20Volume%20Set%20Specification%20v2.0.html

[rxpha3l]

I have no idea why there is a temp commit.

[qkaiser]

Please get rid of temporary commits (can be done with fixup) and delete the erofs leftovers (can be done by rebasing on upstream/main).

[rxpha3l]

Please get rid of temporary commits (can be done with fixup) and delete the erofs leftovers (can be done by rebasing on upstream/main).

everything is now as it should be

[qkaiser]

Commit a14e76a broke some typing, see:

/home/runner/work/unblob/unblob/python/unblob/models.py:427:34 - error: "get_dependencies" is not a known attribute of "None" (reportOptionalMemberAccess)
  /home/runner/work/unblob/unblob/python/unblob/models.py:442:39 - error: Argument of type "list[Path]" cannot be assigned to parameter "inpath" of type "Path" in function "extract"
    "list[Path]" is not assignable to "Path" (reportArgumentType)

We can have a look at it sometime this week.