Automatically try reloading failed images on network changes (#3170)

* Add the networkMonitor to the NSE and delete the old MockMediaLoader

* Generate a MediaLoaderMock through AutoMockable and use it in the MediaProviderTests

* Implement an ImageProvider mechanism that automatically tries reloading images when connectivity is established again and use it for LoadableImages

* Merge the ImageProvider protocol back into the MediaProvider

* Address PR review comments

* Provide a default sdk client request configuration

* Address tasks not automatically cancelling themselves when views get deallocated

UnitTests/Sources/GlobalSearchScreenViewModelTests.swift

@@ -28,7 +28,7 @@ class GlobalSearchScreenViewModelTests: XCTestCase {
     override func setUpWithError() throws {
         cancellables.removeAll()
         viewModel = GlobalSearchScreenViewModel(roomSummaryProvider: RoomSummaryProviderMock(.init(state: .loaded(.mockRooms))),
-                                                imageProvider: MockMediaProvider())
+                                                mediaProvider: MockMediaProvider())
         context = viewModel.context
     }