OpenXML Filter: allow the preservation of available ASCII and high-ANSI font categories

The font categories are specified with extra information in rFonts property most of the time. So, there is a font detection mechanism for merging consequential runs under the bPreferenceAggressiveCleanup conditional parameter. At the same time, the merged document might contain content with other font categories that have been removed by detection logic. Thus, this improvement aims to allow the preservation of available ASCII and high-ANSI font categories under an option (e.g. preserveAsciiAndHighAnsiFontCategoriesOnDetection).