Slight buff to gift packages

[Kuro]

During my last unboxing I opened ~350 gift packages which got me a lot of coins, a lot of crates, a sealed djinn, a sore wrist, and level 100.

Being such a high level already at the time I was guaranteed a reward when I opened them and with scaling I got probably the "maximum" I could have gotten from opening them at the time and in my opinion they became pretty outdated in a short period of time.

I'd rather have them be revamped rather than "buffed". Keep in mind that gift packages are rather slow to come by naturally

- Reduce the amount of coins received from gift packages in general (possibly adjust the scaling)
- Remove item crates as possible rewards
- Replace "empty" with item crates as a "compensation" prize
- Add newer crates as possible rewards
- (maybe) add some pseudo RNG for the 5 inventory slots?

I think these changes would make everyone more happy, the amount of coins coming in would remain the same, lower levels would feel like they're shafted less, higher levels would no longer get item crate 1's, everyone likes inventory slots, and gift packages would get freshened up a bit.