Add a RawKey hook for raw user input hooking

Fixes #1132

README.asciidoc

@@ -1442,6 +1442,8 @@ existing hooks are:
        displayed.
  * `InsertCompletionHide`: Triggered when the insert completion menu gets
        hidden.
+ * `RawKey`: Triggered whenever an key is pressed by the user, the key is
+       used for filtering.
 
 When not specified, the filtering text is an empty string.
 

doc/manpages/hooks.asciidoc

@@ -150,6 +150,10 @@ Default hooks
 *InsertCompletionHide*::
 	Triggered when the insert completion menu gets hidden
 
+*RawKey*::
+	Triggered whenever an key is pressed by the user, the key is
+	used for filtering.
+
 When not specified, the filtering text is an empty string. Note that
 some hooks will not consider underlying scopes depending on what context
 they are bound to be run into, e.g. the `BufWritePost` hook is a buffer

src/client.cc

@@ -85,6 +85,8 @@ bool Client::process_pending_inputs()
             }
             else
                 m_input_handler.handle_key(key);
+
+            context().hooks().run_hook("RawKey", key_to_str(key), context());
         }
         catch (Kakoune::runtime_error& error)
         {