OpenXML Filter: perform the minification of directly specified run properties

It is possible to perform the minification of run properties.

1. A directly specified property is already available in the styles hierarchy of a current run. E.g.: if <w:b/> is a directly specified property in the following run

<w:r>
    <w:rPr>
        <w:rStyle w:val="DefaultParagraphFont"/>
        <w:b/>
    </w:rPr>
    <w:t>Run1</w:t>
</w:r> 

with a style

<w:style w:type="character" w:default="1" w:styleId="DefaultParagraphFont">
    <w:name w:val="Default Paragraph Font"/>
    <w:rPr>
        <w:b/>
    </w:rPr>
</w:style>

then the minified run properties for this run can be just

    <w:rPr>
        <w:rStyle w:val="DefaultParagraphFont"/>
    </w:rPr>

2. A directly specified property has a clearing-formatting value (false, off, none, nil etc.) and it is not available in the styles hierarchy of a current run. E.g.: if <w:b w:val="false"/> is a directly specified property in the following run

<w:r>
    <w:rPr>
        <w:rStyle w:val="DefaultParagraphFont"/>
        <w:b w:val="false"/>
    </w:rPr>
    <w:t>Run1</w:t>
</w:r> 

with a style

<w:style w:type="character" w:default="1" w:styleId="DefaultParagraphFont">
    <w:name w:val="Default Paragraph Font"/>
    <w:rPr>
        <w:i/>
    </w:rPr>
</w:style>

then the minified run properties for this run can be just

    <w:rPr>
        <w:rStyle w:val="DefaultParagraphFont"/>
    </w:rPr>

For more details please refer to the attached sample document with the following UI:

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