Pending Zaps

A fairly large change that replaces Zaps in the codebase with "Zapping"
which is a tagged union consisting of a resolved Zap and a Pending Zap.
These are both counted as Zaps everywhere in Damus, except pending zaps
can be cancelled (most of the time).

damus/Nostr/Relay.swift

@@ -10,21 +10,46 @@ import Foundation
 public struct RelayInfo: Codable {
     let read: Bool?
     let write: Bool?
-    let ephemeral: Bool?
     
-    init(read: Bool, write: Bool, ephemeral: Bool = false) {
+    init(read: Bool, write: Bool) {
         self.read = read
         self.write = write
-        self.ephemeral = ephemeral
     }
 
-    static let rw = RelayInfo(read: true, write: true, ephemeral: false)
-    static let ephemeral = RelayInfo(read: true, write: true, ephemeral: true)
+    static let rw = RelayInfo(read: true, write: true)
+}
+
+enum RelayVariant {
+    case regular
+    case ephemeral
+    case nwc
 }
 
 public struct RelayDescriptor {
-    public let url: RelayURL
-    public let info: RelayInfo
+    let url: RelayURL
+    let info: RelayInfo
+    let variant: RelayVariant
+    
+    init(url: RelayURL, info: RelayInfo, variant: RelayVariant = .regular) {
+        self.url = url
+        self.info = info
+        self.variant = variant
+    }
+    
+    var ephemeral: Bool {
+        switch variant {
+        case .regular:
+            return false
+        case .ephemeral:
+            return true
+        case .nwc:
+            return true
+        }
+    }
+    
+    static func nwc(url: RelayURL) -> RelayDescriptor {
+        return RelayDescriptor(url: url, info: .rw, variant: .nwc)
+    }
 }
 
 enum RelayFlags: Int {