Reduce / improve active zone for the tab close button

[jackburton79]

The active zone for the tab close button is too big, as shown in the screenshot.

[Freaxed]

Linked with this also we should find a way to avoid start dragging a tab when pressing the close button. Dragging with the X icon cause the tab to be dragged but then when released it closes.

[jackburton79]

I had a look at the code, and debugged a bit:
It seems there's something wrong in the logic of WebTabView::_DrawCloseButton() and WebTabView::_CloseRectFrame():

The frame passed to _DrawCloseButton() is passed directly to _CloseRectFrame(), but it's not supposed to be the frame of the button.
Moreover: I printed the values of the frame and they change in a way I don't understand yet.
Needs to be reviewed

[jackburton79]

I tried to fix the problem, but I failed.
By the way, this code is taken from Webpositive which has the same problem.

I opened a ticket there: https://dev.haiku-os.org/ticket/18741