feat(handler): add support for BTRFS stream

Instead of relying on an external CRC32C package, I implemented the algorithm directly in Python.
This manual implementation was necessary because existing libraries lacked the flexibility to support the specific requirement used by BTRFS stream.
The checksum uses the Castagnoli reflected polynomial with a seed of 0x0 and no final XOR operation.
crc32c and crcmod wasn't able to fullfill those requirements and calculate the right checksum.

Author: Corv0O

docs/handlers.md

@@ -8,6 +8,7 @@
     | [`ARC`](#arc) | ARCHIVE | :octicons-check-16: |
     | [`ARJ`](#arj) | ARCHIVE | :octicons-check-16: |
     | [`AUTEL ECC`](#autel-ecc) | ARCHIVE | :octicons-check-16: |
+    | [`BTRFS STREAM`](#btrfs-stream) | FILESYSTEM | :octicons-alert-fill-12: |
     | [`BZIP2`](#bzip2) | COMPRESSION | :octicons-check-16: |
     | [`CAB`](#cab) | ARCHIVE | :octicons-check-16: |
     | [`COMPRESS`](#compress) | COMPRESSION | :octicons-check-16: |
@@ -203,6 +204,26 @@
     === "References"
 
         - [Autel ECC Decryption Script (Sector7)](https://gist.github.com/sector7-nl/3fc815cd2497817ad461bfbd393294cb){ target="_blank" }
+## BTRFS Stream
+
+!!! warning "Partially supported"
+
+    === "Description"
+
+        A BTRFS send stream is a binary format used to transfer btrfs subvolume snapshots between filesystems. It encodes filesystem operations (file creation, directory structure, data writes, metadata) as a sequence of commands that can be replayed by btrfs receive to reconstruct the original snapshot. It supports both full sends (complete snapshot) and incremental sends (diff between two snapshots).
+
+        ---
+
+        - **Handler type:** FileSystem
+        
+
+    === "References"
+
+        - [BTRFS Stream Official Documentation](https://btrfs.readthedocs.io/en/latest/dev/dev-send-stream.html){ target="_blank" }
+
+    === "Limitations"
+
+        - Does not support incremental streams.
 ## bzip2
 
 !!! success "Fully supported"

python/unblob/handlers/__init__.py

@@ -42,6 +42,7 @@
 )
 from .executable import elf, xalz
 from .filesystem import (
+    btrfs_stream,
     cramfs,
     extfs,
     fat,
@@ -141,6 +142,7 @@
     qnx_deflate.QNXDeflateHandler,
     ufs.UFS1Handler,
     ufs.UFS2Handler,
+    btrfs_stream.BTRFSStreamHandler,
 )
 
 BUILTIN_DIR_HANDLERS: DirectoryHandlers = (