BookmarkStyleFeaturesAvailable function

BookmarkStyleFeaturesAvailable loads the selected PDFium module when needed and returns True if the optional FPDFBookmark_GetStyle entry point is present among the module's exports

When the export is available, every TBookmark produced by Bookmarks, Bookmark, BookmarkChildren and BookmarkFrom carries the outline item's /F text flags (ISO 32000-1 Table 153) in its Style set: posItalic stands for bit 1 and posBold for bit 2

Without the export, Style remains empty for every bookmark; bookmark reading is otherwise unaffected

• The export is optional, so deployments running an older pdfium.dll still load and enumerate outlines as usual; only the style flags are absent
• TPdfOutlineStyle is the same set type the Pascal-side TPdfOutlineEditor in FPdfCompress writes, so styles produced by the editor read back through the native API