Grid issues on Cocoa

There seem to be some bugs regarding uiGrid on macOS

Cocoa:
GTK:

```c
#include
#include
#include
#include
#include "ui.h"

int onClosing(uiWindow *w, void *data)
{
uiQuit();
return 1;
}

int main(void)
{
uiInitOptions o;
const char *err;
uiWindow *w;

memset(&o, 0, sizeof (uiInitOptions));
err = uiInit(&o);
if (err != NULL) {
fprintf(stderr, "error initializing ui: %s\n", err);
uiFreeInitError(err);
return 1;
}

w = uiNewWindow("Grid Test", 500, 400, 0);
uiWindowSetMargined(w, 1);

uiGrid *grid = uiNewGrid();
uiGridSetPadded(grid, 1);
uiWindowSetChild(w, uiControl(grid));

uiEntry *name = uiNewEntry();
uiEntry *surname = uiNewEntry();
uiSlider *age = uiNewSlider(0, 100);
uiMultilineEntry *data = uiNewMultilineEntry();
uiMultilineEntrySetText(data, "This is a text.This is a text.\nThis is a text.\nThis is a text.This is a text.\nThis is a text.\n");

uiGridAppend(grid, uiControl(uiNewLabel("name")), 0, 0, 2, 1, 0, uiAlignFill, 0, uiAlignStart);
uiGridAppend(grid, uiControl(uiNewLabel("surname")), 0, 1, 2, 1, 0, uiAlignFill, 0, uiAlignStart);
uiGridAppend(grid, uiControl(uiNewLabel("age")), 0, 2, 2, 1, 0, uiAlignFill, 0, uiAlignStart);

uiGridAppend(grid, uiControl(name), 2, 0, 2, 1, 0, uiAlignFill, 0, uiAlignStart);
uiGridAppend(grid, uiControl(surname), 2, 1, 2, 1, 0, uiAlignFill, 0, uiAlignStart);
uiGridAppend(grid, uiControl(age), 2, 2, 2, 1, 0, uiAlignFill, 0, uiAlignStart);

uiGridAppend(grid, uiControl(data), 4, 0, 1, 3, 1, uiAlignFill, 1, uiAlignFill);

uiWindowOnClosing(w, onClosing, NULL);
uiControlShow(uiControl(w));
uiMain();
return 0;
}
```

----
https://github.com/kusti8/proton-native/issues/55
https://github.com/parro-it/libui-node/issues/63

> Grid does work on macOS; it's just insanely buggy because either Auto Layout is hard or my attempt at making a grid with it is poor (probably the latter), so it only works under specific circumstances... This is an active problem.