[SDK] - Add "Ranked voting" type

[jpaulet]

As organizer, I want to create different voting types, one of the most used one is "ranked voting" (Linear Weighted choice at the ballot protocol). In this voting type, the voter orders the different options by rank, from the 1st to the Nth option.

Then, there are two different results interpretation, we will start with the first one:

• Borda count: Each option is assigned with a specific score (1st option == N-1 score, 2nd option == N-2 score... last option == 0 score). The option with higher score, wins.

In this voting type, the voter must send the complete order (1,2,3,4) and (1,3,4) is not valid as the 2 is missing.

Tasks:

• Review the "Ballot protocol" documentation and implement the "Ranked Voting" in the SDK
• Define the needed parameters (maxCount,minValue,maxValue...)
• Review if we need to add some other extra parameter
• Return the results
• Test it