Decompiler: Add RuleImpliedBool cleanup rule

[LukeSerne]

This new cleanup rule tries to eliminate comparisons with booleans. Such comparisons would often be shown as x != false in decompiler output, which is more complex than strictly necessary - x == true or even just x would suffice. This rule changes such boolean expressions to completely remove the equality check, leading to less complex decompiler output.

Before

void ActivateItem(struct *param_1,int param_2)

{
  if (param_1->mItems[param_2].mIsActive != false)
  {
    param_1->mItems[param_2].mIsActive = false;
  }
  return;
}

After

void ActivateItem(struct *param_1,int param_2)

{
  if (param_1->mItems[param_2].mIsActive)
  {
    param_1->mItems[param_2].mIsActive = false;
  }
  return;
}