simple search functionality

This is the initial phase of the search functionality. It will take user input and interpret it as a word (on the lexemes table), which it will look for and return results matching in sense (from the translations table). The next phase will allow more complicated searches (variable fields) but this one is just to make sure we can query our database.

Rather than wait for a dictionary to be imported, test the code by creating unit tests and injecting some trivial examples to the db.