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.cpp

@@ -74,6 +74,7 @@ bool Epub::parseContentOpf(BookMetadataCache::BookMetadata& bookMetadata) {
   // Grab data from opfParser into epub
   bookMetadata.title = opfParser.title;
   bookMetadata.author = opfParser.author;
+  bookMetadata.language = opfParser.language;
   bookMetadata.coverItemHref = opfParser.coverItemHref;
   bookMetadata.textReferenceHref = opfParser.textReferenceHref;
 
@@ -348,6 +349,15 @@ const std::string& Epub::getAuthor() const {
   return bookMetadataCache->coreMetadata.author;
 }
 
+const std::string& Epub::getLanguage() const {
+  static std::string blank;
+  if (!bookMetadataCache || !bookMetadataCache->isLoaded()) {
+    return blank;
+  }
+
+  return bookMetadataCache->coreMetadata.language;
+}
+
 std::string Epub::getCoverBmpPath(bool cropped) const {
   const auto coverFileName = "cover" + cropped ? "_crop" : "";
   return cachePath + "/" + coverFileName + ".bmp";