Make CalcFocusRect look right

...at least for its (only, it appears) uses at the left of the "Insert -
Hyperlink" dialog and at the left of a Database window.  As aBmpRect and
aTextRect never extend aBoundRect (and aTextRect always leaving a gap left and
right towards aBoundRect, it appears, with the text abbreviated with an ellipsis
if it would be too wide), there should be no need to eventually adjust "the
focus rectangle [to] not touch the text," and for calculating the top of the
focus rect aBoundRect can be used just as well as aBmpRect.  (Though for
calculating the bottom, aBoundRect apparently stretches "too far" compareed to
aTextRect; whatever...  The offsets look somewhat "magic" anyway, but appear to
produce the desired visual results.)

Change-Id: Ic324561294fb6172c0d02a697fc261717e01c87c
Reviewed-on: https://gerrit.libreoffice.org/6165
Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Eike Rathke <erack@redhat.com>
(cherry picked from commit 143bb92761f54cb7b8e41e5ac83bd274d4f7079b)
Signed-off-by: Eike Rathke <erack@redhat.com>