test: Add basic snapshot test coverage for EventView

This commit adds a basic snapshot test for EventView, and also adds some testing infrastructure to help with mocking NostrDB behavior.

Test
----

PASS

Device: iOS 17.0 Simulator
iOS: 17.0
Damus: This commit
Steps: Run `EventViewTests`
Results: Snapshot matches baseline reference added

damusTests/Mocking/MockProfiles.swift

@@ -0,0 +1,28 @@
+//
+//  MockProfiles.swift
+//  damusTests
+//
+//  Created by Daniel D’Aquino on 2023-10-13.
+//
+
+import Foundation
+@testable import damus
+
+// A Mockable `Profiles` class that can be used for testing.
+// Note: Not all methods are mocked. You might need to implement a method depending on the test you are writing.
+class MockProfiles: Profiles {
+    var mocked_profiles: [Pubkey: Profile] = [:]
+    var ndb: Ndb
+    
+    init?(mocked_profiles: [Pubkey : Profile], ndb: Ndb) {
+        self.mocked_profiles = mocked_profiles
+        self.ndb = ndb
+        super.init(ndb: ndb)
+    }
+
+    override func lookup(id: Pubkey) -> NdbTxn<Profile?> {
+        return NdbTxn(ndb: self.ndb) { txn in
+            return self.mocked_profiles[id]
+        }
+    }
+}