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/EventViewTests.swift

@@ -0,0 +1,46 @@
+//
+//  EventViewTests.swift
+//  damusTests
+//
+//  Created by Daniel D’Aquino on 2023-10-13.
+//
+
+import Foundation
+import XCTest
+import SnapshotTesting
+import SwiftUI
+@testable import damus
+
+final class EventViewTests: XCTestCase {
+    
+    override func setUpWithError() throws {
+        // Put setup code here. This method is called before the invocation of each test method in the class.
+    }
+    
+    override func tearDownWithError() throws {
+        // Put teardown code here. This method is called after the invocation of each test method in the class.
+    }
+    
+    func testBasicEventViewLayout() {
+        let test_mock_damus_state = generate_test_damus_state(
+            mock_profile_info: [
+                // Manually mock some profile info so that we have a more realistic-looking note
+                jack_keypair.pubkey: Profile(
+                    name: "jack",
+                    display_name: "Jack Dorsey"
+                )
+            ]
+        )
+        let test_note = NostrEvent(
+            content: "Nostr is the super app. Because it’s actually an ecosystem of apps, all of which make each other better. People haven’t grasped that yet. They will when it’s more accessible and onboarding is more straightforward and intuitive.",
+            keypair: jack_keypair,
+            createdAt: UInt32(Date.init(timeIntervalSinceNow: -60).timeIntervalSince1970)
+        )!
+        
+        let eventViewTest = EventView(damus: test_mock_damus_state, event: test_note).padding()
+        let hostView = UIHostingController(rootView: eventViewTest)
+        
+        // Run snapshot check
+        assertSnapshot(matching: hostView, as: .image(on: .iPhone13(.portrait)))
+    }
+}