Move eval_hook to nu-cmd-base (#10146)

I moved hook to *nu_cmd_base* instead of *nu_cli* because it will enable
other developers to continue to use hook even if they decide to write
their on cli or NOT depend on nu-cli

Then they will still have the hook functionality because they can
include nu-cmd-base

crates/nu-command/src/system/run_external.rs

@@ -1,4 +1,4 @@
-use crate::hook::eval_hook;
+use nu_cmd_base::hook::eval_hook;
 use nu_engine::env_to_strings;
 use nu_engine::CallExt;
 use nu_protocol::{