Consecutive wins reward more orbs

[tmercswims]

An optional feature which would do the following when enabled:

• Every time a user wins another consecutive fish game, their rewards are doubled.
  • So the second win in a row multiplies the reward by 2, the third by 4, the fourth by 8, etc.
• The first win remains the same.
• Applies to any kind of win.

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Implementation notes:

• Winning "exact" will be turned into a multiplier, rather than a separate value.
  • Just like how highlighting your guess is a multiplier.
• This new setting will also be a multiplier.
• Need to keep track of two new things across games:
  • The most recent winner.
  • How many games that user has won consecutively.