[API CHANGE] related tdf#85592: drop duplicate use of .uno:CharBackgroundExt

The primary purpose of CharBackgroundExt is a bool flag to
indicate that the watering-can for text background coloring
is active.
It could also function as a synonym for BackColor in the "execute"
state. A prior (NFC) commit removed internal LO use in this way,
so lets drop the ability to do this altogether.

I'm not sure why anyone would have selected to use CharBackgroundExt
instead of .uno:BackColor in API calls. Perhaps they discovered it via
LO_COLLECT_UIINFO. A google search didn't indicate any significant
use or suggestion to use CharBackgroundExt.

P.S. I'm also trying to deprecate BackColor and replace it with
.uno:CharBackColor - which is what this bug report is actually about.

Change-Id: I8d8a2aedb1af18e4a10ff09ad0dabc58e90514a8
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/138167
Tested-by: Jenkins
Reviewed-by: Justin Luth <jluth@mail.com>
diff --git a/include/svx/tbcontrl.hxx b/include/svx/tbcontrl.hxx
index 194db28..ff7d558 100644
--- a/include/svx/tbcontrl.hxx
+++ b/include/svx/tbcontrl.hxx
@@ -57,7 +57,6 @@

        for character background color (writer)
        Execute-Id      SID_ATTR_CHAR_COLOR_BACKGROUND
                    and SID_ATTR_CHAR_COLOR_BACKGROUND_EXT

        for paragraph background color (writer)
        and cell background color (calc)
diff --git a/sw/sdi/_textsh.sdi b/sw/sdi/_textsh.sdi
index f9b3c84..17eb4e9 100644
--- a/sw/sdi/_textsh.sdi
+++ b/sw/sdi/_textsh.sdi
@@ -1419,7 +1419,6 @@ interface BaseText
    ]
    SID_ATTR_CHAR_COLOR_BACKGROUND_EXT // status()
    [
        ExecMethod = Execute ;
        StateMethod = GetState ;
        DisableFlags="SfxDisableFlags::SwOnProtectedCursor";
    ]
diff --git a/sw/sdi/swriter.sdi b/sw/sdi/swriter.sdi
index 37cb0d3..8cff1d2 100644
--- a/sw/sdi/swriter.sdi
+++ b/sw/sdi/swriter.sdi
@@ -556,7 +556,7 @@ SfxVoidItem ChapterNumberingDialog FN_NUMBERING_OUTLINE_DLG
]

SfxBoolItem CharBackgroundExt SID_ATTR_CHAR_COLOR_BACKGROUND_EXT
(SvxColorItem BackColor SID_ATTR_CHAR_COLOR_BACKGROUND_EXT)
()
[
    AutoUpdate = TRUE,
    FastCall = FALSE,
diff --git a/sw/source/uibase/shells/textsh1.cxx b/sw/source/uibase/shells/textsh1.cxx
index 42ef624..665bae0 100644
--- a/sw/source/uibase/shells/textsh1.cxx
+++ b/sw/source/uibase/shells/textsh1.cxx
@@ -1377,7 +1377,6 @@ void SwTextShell::Execute(SfxRequest &rReq)
        }
        break;
        case SID_ATTR_CHAR_COLOR_BACKGROUND:
        case SID_ATTR_CHAR_COLOR_BACKGROUND_EXT:
        case SID_ATTR_CHAR_COLOR_EXT:
        {
            Color aSet;
@@ -1423,14 +1422,6 @@ void SwTextShell::Execute(SfxRequest &rReq)
                    rWrtSh.SetAttrItem(
                        SvxColorItem(aSet, RES_CHRATR_COLOR) );
            }
            else if (nSlot == SID_ATTR_CHAR_COLOR_BACKGROUND_EXT)
            {
                if (!pApply || pApply->nColor != SID_ATTR_CHAR_COLOR_BACKGROUND)
                {
                    aTempl.nColor = SID_ATTR_CHAR_COLOR_BACKGROUND;
                    rEdtWin.SetApplyTemplate(aTempl);
                }
            }
            else
            {
                if(!pApply || pApply->nColor != nSlot)