purple: add subscriber number on the Purple supporter badge

This change adds an subscriber number to the supporter badge.

Testing
--------

PASS

Device: iPhone 15 simulator
iOS: 17.2
Damus: This commit
damus-api: `53fd7fef1c8c0bbf82bb28d1d776e45379433d23`
Setup:
- `damus-api` running on `npm run dev` mode
- Damus configured to enable experimental Purple support + localhost mode
Test steps:
1. Wipe local database and rerun server
2. Purchase purple using In-app purchase (Xcode environment) flow
3. Make sure that badge to the side of the user's name on the event shows a golden star without any ordinal numbers
4. Make sure that the badge to the side of the user's name on the profile page shows a golden star with the text "1st"
5. Repeat steps 2–4 and make sure the text says "2nd"
6. Look at the SupporterBadge view previews. Ordinals should show up correctly for all previews (They should always show up, no matter the number)

Closes: https://github.com/damus-io/damus/issues/1873
Signed-off-by: Daniel D’Aquino <daniel@daquino.me>
Reviewed-by: William Casarin <jb55@jb55.com>
Signed-off-by: William Casarin <jb55@jb55.com>

damus/Components/Gradients/GoldSupportGradient.swift

@@ -7,7 +7,7 @@
 
 import SwiftUI
 
-fileprivate let gold_grad_c1 = hex_col(r: 226, g: 168, b: 0)
+fileprivate let gold_grad_c1 = DamusColors.gold
 fileprivate let gold_grad_c2 = hex_col(r: 249, g: 243, b: 100)
 
 fileprivate let gold_grad = [gold_grad_c2, gold_grad_c1]