feat: dict based Hyphenation (#305)

## Summary

* Adds (optional) Hyphenation for English, French, German, Russian
languages

## Additional Context

* Included hyphenation dictionaries add approximately 280kb to the flash
usage (German alone takes 200kb)
* Trie encoded dictionaries are adopted from hypher project
(https://github.com/typst/hypher)
* Soft hyphens (and other explicit hyphens) take precedence over
dict-based hyphenation. Overall, the hyphenation rules are quite
aggressive, as I believe it makes more sense on our smaller screen.

---------

Co-authored-by: Dave Allie <dave@daveallie.com>

lib/Epub/Epub/parsers/ContentOpfParser.h

@@ -13,6 +13,7 @@ class ContentOpfParser final : public Print {
     IN_METADATA,
     IN_BOOK_TITLE,
     IN_BOOK_AUTHOR,
+    IN_BOOK_LANGUAGE,
     IN_MANIFEST,
     IN_SPINE,
     IN_GUIDE,
@@ -34,6 +35,7 @@ class ContentOpfParser final : public Print {
  public:
   std::string title;
   std::string author;
+  std::string language;
   std::string tocNcxPath;
   std::string tocNavPath;  // EPUB 3 nav document path
   std::string coverItemHref;