Minor optimisations and bug fixes

Fix bug in mt_mpmc.c, in Linux mutexes are not recursive.
Add arena_trim_string() to the arena API
Removing arena->path, now paths are pushed to arena->metadata
Replacing fe->owner[128] with char *owner; the owner is not pushed as a
string to arena->metadata and trimed with arena_trim_string()
Improving cache locality in arena->metadata, the memory layout is not
fe; fe->path; fe->owner.
Cache aligning all arenas except HasherContext->arena to sizeof(void *).
Pushing elements one by one instead of snprintf() in finalize_file() and
hash_worker().
Getting the full path of current directory instead of "."
Fixing bug in path formating, this allow us to remove normalize_path()
from the hot loop.

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.20)
-project(filehasher
+project(dfin
     VERSION 1.0.0
-    DESCRIPTION "High-performance file hasher with I/O Ring/io_uring support"
+    DESCRIPTION "High-performance duplicate finder with I/O Ring/io_uring support"
     LANGUAGES C
 )
 
@@ -106,7 +106,7 @@ endif()
 # ---------------------------------------------------------------------------
 
 set(SOURCES
-    file_hasher.c
+    duplicate_finder.c
     xxhash.c
     xxh_x86dispatch.c
 )
@@ -116,7 +116,7 @@ set(HEADERS
     arena.h
     base.h
     xxhash.h
-    lf_mpmc.h
+    mt_mpmc.h
 )
 
 # ---------------------------------------------------------------------------
@@ -281,4 +281,4 @@ message(STATUS "  Compiler: ${CMAKE_C_COMPILER}")
 message(STATUS "  Build Type: ${CMAKE_BUILD_TYPE}")
 message(STATUS "  Generator: ${CMAKE_GENERATOR}")
 message(STATUS "  Platform: ${PLATFORM_NAME}")
-message(STATUS "----------------------------------------")
+message(STATUS "----------------------------------------")