refactor: Improve WebDAV VFS implementation

- Removed unnecessary dependencies and improved code structure in `webdav` module.
- Updated VFS configuration to use global VFS instance for WebDAV app.
- Renamed example VFS file to reflect WebDAV functionality.
- Removed redundant code and simplified app initialization.
- Used the vfs interface to interact with files and dirs.

lib/vfs/vfsnested/vfsnested.v

@@ -5,7 +5,7 @@ import freeflowuniverse.herolib.vfs.vfscore
 // NestedVFS represents a VFS that can contain multiple nested VFS instances
 pub struct NestedVFS {
 mut:
-	vfs_map map[string]vfscore.VFSImplementation // Map of path prefixes to VFS implementations
+	vfs_map map[string]vfscore.VFSImplementation @[skip] // Map of path prefixes to VFS implementations
 }
 
 // new creates a new NestedVFS instance

lib/vfs/webdav/app.v

@@ -8,10 +8,9 @@ import freeflowuniverse.herolib.vfs.vfscore
 struct App {
 	vweb.Context
 	user_db map[string]string @[required]
-	// root_dir pathlib.Path      @[vweb_global]
 pub mut:
 	lock_manager LockManager
-	vfs          vfscore.VFSImplementation
+	vfs          vfscore.VFSImplementation @[vweb_global]
 	server_port  int
 	middlewares  map[string][]vweb.Middleware
 }
@@ -20,16 +19,13 @@ pub mut:
 pub struct AppArgs {
 pub mut:
 	server_port int = 8080
-	// root_dir    string            @[required]
-	user_db map[string]string @[required]
-	vfs     vfscore.VFSImplementation
+	user_db     map[string]string @[required]
+	vfs         vfscore.VFSImplementation
 }
 
 pub fn new_app(args AppArgs) !&App {
-	// root_dir := pathlib.get_dir(path: args.root_dir, create: true)!
 	mut app := &App{
-		user_db: args.user_db.clone()
-		// root_dir:    root_dir
+		user_db:     args.user_db.clone()
 		server_port: args.server_port
 		vfs:         args.vfs
 	}

lib/vfs/webdav/methods.v

@@ -1,11 +1,8 @@
 module webdav
 
-import freeflowuniverse.herolib.core.pathlib
 import freeflowuniverse.herolib.ui.console
-import freeflowuniverse.herolib.vfs.ourdb_fs
 import encoding.xml
 import net.urllib
-import os
 import vweb
 
 @['/:path...'; options]