feat(developer, web): predictive modeling for morphologically complex languages

From the Community forums at https://community.software.sil.org/t/keyman-roadmap-march-2020/822/29:

> Being able to identify in the tsv file what types of words can take what types of prefixes and in our language’s case clitic pronouns would allow for prediction of at least suffixes, but also better predictions on verbs, nouns, or whatever should follow.

Also, later in the same post:

> Hunspell has at least been barking up this tree for more than a decade and Fieldworks grammar data can be used to help with word prediction.
>
> Many languages will require specific greetings to be the way you open up a text message. Having those float to the top of suggestions for a new text would be useful. Things like Hola, Assalam Alaykum, Good Evening. These type of message openers could be designated in a TSV file.