Uniformize/fix page titles and make “Tatoeba” translatable

This formats all the page titles to “＜page-title＞ - Tatoeba“ with both the ＜page-title＞ and the “- Tatoeba” parts translatable. It otherwise adds titles to pages where it was missing. This way, glancing at a browser tab won’t show you “Tatoeba” everywhere but rather the actual page name. I included the **-** sign in the translation because there are languages where the typography changes, to my knowledge French uses **—** or **–** instead.