refactor: migrate all servers, apps, binaries to libkos

crates/apps/echo/Cargo.toml

@@ -10,5 +10,5 @@ bench = false
 
 [dependencies]
 types = { workspace = true }
-userspace = { workspace = true }
-userspace-rt = { workspace = true }
+
+libkos = { workspace = true }

crates/apps/echo/src/main.rs

@@ -1,10 +1,10 @@
 #![no_std]
 #![no_main]
 
-extern crate userspace_rt;
+extern crate libkos;
 
 use types::bounded::CapSlot;
-use userspace::syscall;
+use libkos::syscall;
 
 #[unsafe(no_mangle)]
 extern "C" fn main() {