imwayland: make preedit use real highlight instead of bold for style
See #5035
Mutter doesn't set anchor for preedit (mutter cursor always send equal value of anchor), so tested with kwin_wayland and fcitx5.
Edited by Weng Xuetian
See #5035
Mutter doesn't set anchor for preedit (mutter cursor always send equal value of anchor), so tested with kwin_wayland and fcitx5.