Port in Kitty's improved find/replace text floater experience

indra/llui/lltextbase.cpp

indra/llui/lltextbase.h

indra/llui/lltexteditor.cpp

indra/llui/lltexteditor.h

indra/newview/CMakeLists.txt

indra/newview/llfloatersearchreplace.cpp

indra/newview/llfloatersearchreplace.h

indra/newview/llpreview.cpp

indra/newview/llpreviewnotecard.cpp

indra/newview/llpreviewnotecard.h

indra/newview/llpreviewscript.cpp

indra/newview/llpreviewscript.h

indra/newview/llviewerfloaterreg.cpp

indra/newview/skins/alchemy/colors.xml

indra/newview/skins/default/colors.xml

...a/newview/skins/default/xui/en/floater_search_replace.xml

indra/newview/skins/default/xui/en/panel_script_ed.xml

...wview/skins/default/xui/en/widgets/simple_text_editor.xml