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/HomeScreen/View/HomeScreenRoomCell.swift

@@ -38,7 +38,7 @@ struct HomeScreenRoomCell: View {
             .accessibilityElement(children: .combine)
         }
         .buttonStyle(HomeScreenRoomCellButtonStyle())
-        .accessibilityIdentifier("roomName:\(room.name)")
+        .accessibilityIdentifier(A11yIdentifiers.homeScreen.roomName(room.name))
         .overlay(alignment: .bottom) {
             Divider()
                 .frame(height: 0.5)