AUTH/4/1 Update sentence storage

[AppolinFotso]

We need to be storing the input sentences in a better way!

Modify the sentences table, add the following two columns:

• Source (string)
• Count (integer)

Fill this table with the 12 example sentences we already have hardcoded. Use original.txt for the Source column and the count should be incremental from 1-12.

The API should return a random sentence from this table whenever we ask for a new sentence. It should return both the ID (primary key) and the sentence itself. It doesn't need to return the other columns (source and count).

The frontend needs to make sure to store the ID of the sentence that was obtained and use that when sending back the suggestion+user interaction to the backend. The sentence database should not be modified anymore when the user clicks on a suggestion, as all the sentences are there already

[AppolinFotso]

PR #38