Apply autodiscount if multiple code satisfies the auto discount condi…

…tion

Changes included in this PR fixes the following usecase -

1. Consider the below two discount codes which are applied to different price options but to the same event types.

• eventmem20: $20 off for members discount is applied to event type Fundraiser and to price field options $80, $100, etc.

• eventmem35: $35 off for members discount is applied to event type Fundraiser and to price field options $165, $400, etc.

2. The first price field $80, $100 is used in EventA and the second ($165, $400) is used in EventB.

3. When the registration page is loaded for EventA - the auto discount for eventmem20 is applied correctly.

4. When the registration page is loaded for EventB - the discount eventmem35 is not applied automatically.

CiviDiscount only grabs the first discount instance for the event type.