Add bolt11 parser and Invoice View

Changelog-Added: Display bolt11 invoice widgets on posts

damus/Components/InvoiceView.swift

@@ -0,0 +1,53 @@
+//
+//  InvoiceView.swift
+//  damus
+//
+//  Created by William Casarin on 2022-10-18.
+//
+
+import SwiftUI
+
+struct InvoiceView: View {
+    let invoice: Invoice
+    
+    var PayButton: some View {
+        Button("Pay") {
+            guard let url = URL(string: "lightning:" + invoice.string) else {
+                return
+            }
+            UIApplication.shared.open(url)
+        }
+        .buttonStyle(.bordered)
+    }
+    
+    var body: some View {
+        ZStack {
+            RoundedRectangle(cornerRadius: 20)
+                .foregroundColor(.secondary.opacity(0.1))
+            
+            VStack(alignment: .trailing, spacing: 12) {
+                HStack {
+                    Label("", systemImage: "bolt.fill")
+                        .foregroundColor(.orange)
+                    Text("Lightning Invoice")
+                }
+                Divider()
+                Text(invoice.description)
+                Text("\(invoice.amount / 1000) sats")
+                    .font(.title)
+                PayButton
+                    .zIndex(5.0)
+            }
+            .padding()
+        }
+    }
+}
+
+let test_invoice = Invoice(description: "this is a description", amount: 10000, string: "lnbc100n1p357sl0sp5t9n56wdztun39lgdqlr30xqwksg3k69q4q2rkr52aplujw0esn0qpp5mrqgljk62z20q4nvgr6lzcyn6fhylzccwdvu4k77apg3zmrkujjqdpzw35xjueqd9ejqcfqv3jhxcmjd9c8g6t0dcxqyjw5qcqpjrzjqt56h4gvp5yx36u2uzqa6qwcsk3e2duunfxppzj9vhypc3wfe2wswz607uqq3xqqqsqqqqqqqqqqqlqqyg9qyysgqagx5h20aeulj3gdwx3kxs8u9f4mcakdkwuakasamm9562ffyr9en8yg20lg0ygnr9zpwp68524kmda0t5xp2wytex35pu8hapyjajxqpsql29r", expiry: 604800, payment_hash: Data(), created_at: 1666139119)
+
+struct InvoiceView_Previews: PreviewProvider {
+    static var previews: some View {
+        InvoiceView(invoice: test_invoice)
+            .frame(width: 200, height: 200)
+    }
+}

damus/Components/InvoicesView.swift

@@ -0,0 +1,35 @@
+//
+//  InvoicesView.swift
+//  damus
+//
+//  Created by William Casarin on 2022-10-18.
+//
+
+import SwiftUI
+
+struct InvoicesView: View {
+    var invoices: [Invoice]
+    
+    @State var open_sheet: Bool = false
+    @State var current_invoice: Invoice? = nil
+    
+    var body: some View {
+        TabView {
+            ForEach(invoices, id: \.string) { invoice in
+                InvoiceView(invoice: invoice)
+                .tabItem {
+                    Text(invoice.string)
+                }
+                .id(invoice.string)
+            }
+        }
+        .frame(height: 200)
+        .tabViewStyle(PageTabViewStyle())
+    }
+}
+
+struct InvoicesView_Previews: PreviewProvider {
+    static var previews: some View {
+        InvoicesView(invoices: [Invoice.init(description: "description", amount: 10000, string: "invstr", expiry: 100000, payment_hash: Data(), created_at: 1000000)])
+    }
+}