Support Ranked Preference question and answer types

[mgdemel]

We need two types of answers, those for the Likert scale, and Drag to re-order prioritization, as well as possible other types in the future.

We already support Likert, but Ranked Preference is still missing. This will need implementation in:

1. The matching algorithm
2. Svelte
3. Strapi
4. Candidate App

In the Candidate App (on the /candidate/(protected)/questions/[questionId] route), specific care must be taken with temporary saving of the answers in localStorage. Probably the best option is to build a (de)serialize method to all Question objects so that their answers can be stored as strings (to which type localStorage converts all inputs).

[kaljarv]

We already support Likert, but Ranked Preference is still missing. This will need implementation in:

1. The matching algorithm
2. Svelte
3. Strapi