Change page when run out of vocab activities

[Kelrap]

Proposed Feature
Describe the feature that should be added.

When a user gets perfect on enough activities, those activities don't appear on the vocab activity lineup, so the user is left with nothing to do. Make the page when that happens celebratory, and suggest what the user can do to get more activities. Something like, "Wow, you know everything! Increase your CEFR level to up the difficulty, and collect more vocab to unlock more vocab practice activities."

Rationale
Explain how the feature would improve the user experience.

The current page makes it seem like an error occurred, and suggest loading more when it doesn't do anything.

To Test
After implementation, include a list of changes to be looked over

1. Change to language you're confident in, that has few vocab words in analytics
2. Start vocab activity
3. Get as many questions perfect as possible
4. Repeat until there are no more questions
5. Should show new page

[TigToggle]

@ggurdin Doesn't appear to be working!
I'm still getting 'Oops, something went wrong...' and a Try Again button that doesn't do anything.

[ggurdin]

@TigToggle Thanks! Which account are you testing with?

[TigToggle]

@ggurdin Test41 , language En -> Fr