No NK_EDIT_DEACTIVATED flag is returned when switching from one nk_edit_string to a previous one

When an `nk_edit_string` widget is active, the expected behaviour is that the return flags include `NK_EDIT_DEACTIVATED` whenever it becomes inactive. It works for most cases, but not if you switch straight to a different `nk_edit_string`, specifically one that was submitted earlier in the frame.

It is reproducible with the following code, notice that the deactivation message does not get triggered when clicking the first textbox while the second is active.
```C++
static char text[2][64];
static int text_len[2];
nk_flags return_flags[2];
nk_layout_row_dynamic(ctx, 30, 1);

for (int i = 0; i < 2; i++) {
return_flags[i] = nk_edit_string(ctx, NK_EDIT_FIELD, text[i], &text_len[i], 64, nk_filter_default);

if (return_flags[i] & NK_EDIT_ACTIVATED)
std::cout << "activated " << i << std::endl;
if (return_flags[i] & NK_EDIT_DEACTIVATED)
std::cout << "deactivated " << i << std::endl;
}
```

The bug arises from the fact that when the earlier widget becomes active, it already overwrites the name of the current active edit field to its own id, so information on the previous frame's active edit field is lost too early.

1. Widget A sees it became active and updates `ctx->current.edit.name` to its index/hash
https://github.com/Immediate-Mode-UI/Nuklear/blob/0319c0ff3b36006a377cd30fa5eb39672ecb3c83/nuklear.h#L28071-L28074
2. Widget B determines it is inactive because its index/hash no longer matches `ctx->current.edit.name`, and this falsely becomes `prev_state`
https://github.com/Immediate-Mode-UI/Nuklear/blob/0319c0ff3b36006a377cd30fa5eb39672ecb3c83/nuklear.h#L27449
4. Then when the mouse click is processed and it is found to be outside the bounding box, the widget doesn't register a change because `prev_state` is already 0.
https://github.com/Immediate-Mode-UI/Nuklear/blob/0319c0ff3b36006a377cd30fa5eb39672ecb3c83/nuklear.h#L27477-L27478

(Tested on the most up-to-date version at the time of posting)

Start in nuklear.h around lines 27449, 27477-27478, and 28071-28074, then run the two-widget nk_edit_string reproduction from the issue. Trace how the active edit field name changes when switching widgets and ensure the previously active widget still returns NK_EDIT_DEACTIVATED when focus moves to an earlier widget.

Written by the indexing model from the issue text.