Refactor, decompose and add previews. Fix part of speech sheet pop over

Toki Trainer/ViewModels/TokiDictionaryViewModel.swift

@@ -44,6 +44,11 @@ class TokiDictionaryViewModel: ObservableObject {
         dictionary = []
         translatedDictionary = []
         
+        if input.isEmpty {
+            dictionary = fullDictionary
+            translatedDictionary.append(TokiSubWordListEntry("Dictionary"))
+        }
+        
         let capturePattern = #"(\w+)"#
         let captures = self.searchStringForRegex(string: input, regex: capturePattern)
         for capture in captures {