Increased CPU utilization due to SC_WIN_IDLE messages

I use Scintilla within a Windows dialog.
If I now use multiple views within the dialog,
then there is increased CPU utilization due to SC_WIN_IDLE messages.

Here is an example setup for illustration
The DIAGNOSTICS dialog has the following methods, among others

```Rust
    ...
    pub fn create_doc(&self) -> isize {
        self.editor.call(SCI_CREATEDOCUMENT, 0, 0)
    }

    pub fn release_doc(&self, doc: isize) {
        self.editor.call(SCI_RELEASEDOCUMENT, 0, doc);
    }

    pub fn switch_doc(& mut self, new_doc: isize) {
        if new_doc != self.current_doc {
            let current_doc = self.editor.call(SCI_GETDOCPOINTER, 0, 0);
            self.editor.call(SCI_ADDREFDOCUMENT, 0, current_doc);
            self.editor.call(SCI_SETDOCPOINTER, 0, new_doc);
            self.editor.call(SCI_SETTABWIDTH, 2, 0);
            self.current_doc = new_doc;
        }
    }
    ...
```

other code calls it

```Rust
    if self.diagnostic_view == -1 {
        self.diagnostic_view = DIAGNOSTICS.create_doc();
    }
    DIAGNOSTICS.switch_doc(self.diagnostic_view);
```

If this Scintilla control now receives text,
it results in a large number of SC_WIN_IDLE (5001) messages being received,
which leads to increased CPU utilization.

procid  dialog       timestamp ms
[16816] diagnostics  1737838727402 HWND(0xd0866) 5001 WPARAM(2273467515) 
LPARAM(0)
[16816] diagnostics  1737838727409 HWND(0xd0866) 5001 WPARAM(2273467515) 
LPARAM(0)
[16816] diagnostics  1737838727417 HWND(0xd0866) 5001 WPARAM(2273467515) 
LPARAM(0)
[16816] diagnostics  1737838727420 HWND(0xd0866) 5001 WPARAM(2273467515) 
LPARAM(0)
[16816] diagnostics  1737838727422 HWND(0xd0866) 5001 WPARAM(2273467515) 
LPARAM(0)
...

which only subsides again when the document no longer contains any text.

My subclassing code

```Rust
extern "system" fn subclassed_scintilla_proc(hwnd: HWND, msg: u32, wparam: 
WPARAM, lparam: LPARAM, _uid_subclass: usize, _dw_ref_data: usize) -> 
LRESULT {
    use std::time::{SystemTime, UNIX_EPOCH};
    if let Ok(n) = SystemTime::now().duration_since(UNIX_EPOCH) {
        plugin_utils::helper::output_debug_string(&format!("diagnostics 
{:>14?} {hwnd:?} {msg} {wparam:?} {lparam:?} \n", n.as_millis()));
    }

    if msg == WM_GETDLGCODE {
        return LRESULT((DLGC_WANTARROWS | DLGC_WANTCHARS) as isize);
    }
    unsafe { DefSubclassProc(hwnd, msg, wparam, lparam) }
}
```

Btw. even if I do not subclass the Scintilla control, the CPU load is 
increased.
Am I missing something here? 

Thx
Eren

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