Little nightmare fix

[nwjgit]

closes: oldschoolgg/oldschoolbot#1023

Description:

• Fixes Little nightmare drop rates.
  "The pet has a 1/800 drop rate in the original encounter, increasing by said amount for every additional player in the room when the fight started; 1/1600 in a duo, 1/2400 in a trio, 1/3200 in a 4-man and 1/4000 in a 5 or higher man encounter. At Phosani's Nightmare, the pet has a flat 1/1400 drop rate." Source: https://oldschool.runescape.wiki/w/Little_nightmare

Changes:

• Makes Little nightmare drop scale based on party size.

• 5% for MVP

• "Mass nightmare" is capped at user + 3 simulated users but I still added a check to make sure this never goes above 4000.

• I have tested all my changes thoroughly.

[nwjgit]

The commented out leagues Highscore checks are causing the test to fail. I'm guessing that's because Leagues 4 is releasing tomorrow and messing with the Highscores.