feat(scanner): regex metadata extraction (#1669)

feat(metadata): extract metadata from file paths with regex rules (#1669)

Let libraries define ordered regex rules that read title, authors, series,
series number and dates from each book's path relative to its library folder.
Run rules in a bounded worker pool, honour source precedence and field locks,
and apply them on scans, uploads and watcher moves. Also retry unprobed M4B
tag writes with the mp4 muxer.

Closes #1351

Co-authored-by: neon <18559658+neonsolstice@users.noreply.github.com>

server/test/e2e/authorization-matrix/route-inventory/manifest.json

@@ -1,5 +1,5 @@
 {
-  "totalRoutes": 660,
+  "totalRoutes": 662,
   "byPermission": {
     "(none)": 286,
     "Permission.ManageMetadataConfig": 41,
@@ -7,7 +7,7 @@
     "Permission.LibraryEditMetadata": 35,
     "Permission.BookDockAccess": 17,
     "Permission.ManageAppSettings": 62,
-    "Permission.ManageLibraries": 22,
+    "Permission.ManageLibraries": 24,
     "Permission.ManageUsers": 13,
     "Permission.ManageEmail": 8,
     "Permission.KoboSync": 13,