[MSPAINT] Realize Masked Skew

- Add CreateMonoBitmap and CopyMonoImage functions to dib.cpp.
- Add bMono parameter to SkewDIB function.
- Add hbmMask parameter to InsertFromHBITMAP function.
- Add ToolsModel::IsSelection.
CORE-18867

base/applications/mspaint/toolsmodel.cpp

@@ -40,6 +40,11 @@ ToolBase *ToolsModel::GetOrCreateTool(TOOLTYPE nTool)
     return m_tools[nTool];
 }
 
+BOOL ToolsModel::IsSelection() const
+{
+    return (GetActiveTool() == TOOL_RECTSEL || GetActiveTool() == TOOL_FREESEL);
+}
+
 int ToolsModel::GetLineWidth() const
 {
     return m_lineWidth;