Align accessibility IDs with elementX android (#567)

* Rename onboarding and login user/pass accessibility ids.

* Refactor remaining server change accessibility IDs

* Avoid accessibilityIdentifier spreading to all decorations on the textBox.

Required because otherwise there are multiple items tagged with the accessibilityId
which means we can't click on "the" item.

* Move all accessibility identifiers to `AccessibilityIdentifiers.swft`
- use same naming convention on all of them
- remove the unused ones
- fix build errors in integration tests and invalid identifiers (still broken until autodiscovery lands on rosa)

---------

Co-authored-by: Stefan Ceriu <stefanc@matrix.org>

ElementX/Sources/Screens/RoomScreen/View/RoomHeaderView.swift

@@ -29,7 +29,7 @@ struct RoomHeaderView: View {
                 .accessibilityHidden(true)
             Text(context.viewState.roomTitle)
                 .font(.element.headline)
-                .accessibilityIdentifier("roomNameLabel")
+                .accessibilityIdentifier(A11yIdentifiers.roomScreen.name)
         }
         // Leading align whilst using the principal toolbar position.
         .frame(maxWidth: .infinity, alignment: .leading)
@@ -45,7 +45,7 @@ struct RoomHeaderView: View {
                             contentID: context.viewState.roomId,
                             avatarSize: .room(on: .timeline),
                             imageProvider: context.imageProvider)
-            .accessibilityIdentifier("roomAvatarImage")
+            .accessibilityIdentifier(A11yIdentifiers.roomScreen.avatar)
     }
 }