Screenshot tests (#130)

* #9 Add snapshot testing library

* #9 Create script to boot test simulators

* #9 Create the UI test plan

* #9 Create shared schemes for test targets

* #9 Disable split view for UI tests

* #9 Fix fastlane dependencies

* #9 Add snapshot testing to the application

* #9 assert screenshots

* #9 fix swipe gestures on iPad

* #9 Fix accessing items in session verification screen

* #9 Workaround for flaky unit test

* #9 Specify scheme for alpha build

* #9 Add reference screenshots

* Update python script path and check assets for png check

* Update script path

* Use static timezone for simulator time

* Fix build after SwiftFormat

* Add changelog

* Upload failed screenshots artifact

* Always upload artifacts

* Update boot simulator script

* Update simulator overridden time

* Install pytz before tests

* Get time from Ruby script

* Disable SwiftUI animation when running UI tests

* Update screenshots after animation setting

* Include reference images in the artifact

* Update matching precision

* Update image matching precision & revert artifact content

* Include Xcode result in the artifact

* Update test output directory

* Disable gradient on splash screen for tests

* Tap next button explicitly

* Wait a bit before checking alert

* Wait 1 second

* Run SwiftFormat on project

* Ignore temporary screenshots

* Fix most of the PR remarks

* Fix conflicts

* Bump Python version to 3

* Update reference screenshots for authentication screens

* Update SwiftFormat

* Fix flakey session verification test.

* Update scheme.

Co-authored-by: Doug <douglase@element.io>

ElementX.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved

@@ -66,7 +66,7 @@
     {
       "identity" : "matrix-rust-components-swift",
       "kind" : "remoteSourceControl",
-      "location" : "https://github.com/matrix-org/matrix-rust-components-swift",
+      "location" : "https://github.com/matrix-org/matrix-rust-components-swift.git",
       "state" : {
         "revision" : "1358c9c2a85cfb5fc1bfadce13565e02618725d4",
         "version" : "1.0.13-alpha"
@@ -81,6 +81,15 @@
         "version" : "7.18.1"
       }
     },
+    {
+      "identity" : "swift-snapshot-testing",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/pointfreeco/swift-snapshot-testing.git",
+      "state" : {
+        "revision" : "f8a9c997c3c1dab4e216a8ec9014e23144cbab37",
+        "version" : "1.9.0"
+      }
+    },
     {
       "identity" : "swiftstate",
       "kind" : "remoteSourceControl",