Loyality credential data elements

[davidz25]

The newly added loyality card credential has a lot of data elements that don't make sense for a loyalty card, including

• birth_date
• age_over_NN
• sex

We should remove those. This will also make use-cases such as "present both loyalty-card (for proof of membership) and mDL (for proof of legal age)" make more sense.

On the other hand, most loyality card has the notion of different tiers (basic, silver, gold, platinum, elite) but we don't currently model this. Maybe we should add a data-element with the name tier and type tstr for this.

Also, we should rename the object/class from LoyaltyID to just Loyalty.

[hanluOMH]

Create PR:#1305