Diagnostics for oncall in header files - add detection

Summary:
* We detect if an oncall attribute is in the header .hrl file
* For now we wonly display a message. Next diff will have the fix for this suggested too

Reviewed By: alanz

Differential Revision: D63696175

fbshipit-source-id: d14658dac38e9dd99a8a06dc77c80bed02407c50

Author: bgsmeta

crates/ide/src/diagnostics/unused_include.rs

@@ -590,23 +590,6 @@ foo() -> ok.
         )
     }
 
-    #[test]
-    fn not_used_for_oncall_attribute() {
-        check_diagnostics(
-            r#"
-//- /src/main.erl
--module(main).
-  -include("header.hrl").
-%%^^^^^^^^^^^^^^^^^^^^^^^ 💡 warning: Unused file: header.hrl
-
-foo() -> ok.
-
-//- /src/header.hrl
--oncall("mary").
-"#,
-        )
-    }
-
     #[test]
     fn fixes_unused_include() {
         check_fix(