Searches for the style. Adds if not found (optionally)
function FindSuchStyle(Style: TRVListInfo; AddIfNotFound: Boolean): Integer;
This method searches for the style having all properties of Style.
If AddIfNotFound=True and style is not found, it adds a new style to the end of collection and assigns all properties of Style to it. The created style has Standard property = False.
The following properties are ignored when comparing styles:
Index of style, or -1 if not found (and not added).