Update status bar labels properly after width change in wxMSW.

Update status bar labels properly after width change in wxMSW.

The labels were not updated (i.e. ellipsized or, on the contrary, displayed in
full) correctly after a status bar field was changed; there was even a FIXME
comment about this in the code.

Fix this by calling DoUpdateStatusText() when the field width is changed and
also update the field width after resetting the existing tooltips.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@69380 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775