Order word learned list

[diprefranco]

As a user
I want to order alphabetically the list of words learned
To see the list order or in the original order

---------- Acceptance criteria ----------

On new lesson screen

• Show title "Words learned" on the list of words learned, only when the list has at least one word.
• Next to the mencioned tittle show an order icon.
• By default show the words learned in the original order (as the user registered them) and show the non-alphabetically order icon.
• When the user clicks on the order icon show the words order alphabetically and change the icon to the alphabetically order icon.
• When the user clicks on the alphabetically order icon show the words in the original order and change the icon to the non-alphabetically order icon.
• Show a tooltip with an explanation.

[diprefranco]

• Rename wordsLearnt variable to wordsLearned.