restore the extract function for server functions (#4849)

* restore the extract function for server functions

* fix compilation

* Move most fields under one shared lock

* fix typo

* fix clippy

* restore somewhat misleading FromRequest bound

* remove unused import

* fix doc links

packages/fullstack-core/Cargo.toml

@@ -29,6 +29,8 @@ inventory = { workspace = true }
 serde_json = { workspace = true }
 generational-box = { workspace = true }
 futures-util = { workspace = true, features = ["std"] }
+tokio = { workspace = true, features = ["rt"] }
+parking_lot = { workspace = true }
 
 [features]
 web = []