Rework Upload internals to use MVVM (#33307)

* Initial reword of upload to MVVM.

* Update tests

* More incremental improvements

* Refactor tests to use helper method for composer uploads.

* Add drag and drop tests

* lint

* Add commentary

* fixup test

* More precise selector

* Retarget uploads

* lint

* fixup

* one more type

* update snap

* Fixup composerUploadFiles

* fix import

* lint

* Copy and paste fixes too

* Add tests for pasting

* Add tests for pasting files.

* Remove redundant fn

* rm comment

* tidy up

* Test cleanup

* More clean up

* another fix

* Use condensed version

* Cleanup tests

* more cleaning

* last bity

* s/throw Error/throw new Error/

apps/web/test/unit-tests/components/views/rooms/SendMessageComposer-test.tsx

@@ -31,6 +31,7 @@ import { doMaybeLocalRoomAction } from "../../../../../src/utils/local-room";
 import { addTextToComposer } from "../../../../test-utils/composer";
 import { ScopedRoomContextProvider } from "../../../../../src/contexts/ScopedRoomContext.tsx";
 import { SdkContextClass } from "../../../../../src/contexts/SDKContext.ts";
+import { RoomUploadContextProvider } from "../../../../../src/viewmodels/room/RoomUploadViewModel.tsx";
 
 jest.mock("../../../../../src/utils/local-room", () => ({
     doMaybeLocalRoomAction: jest.fn(),
@@ -187,8 +188,10 @@ describe("<SendMessageComposer/>", () => {
         };
         const getRawComponent = (props = {}, roomContext = defaultRoomContext, client = mockClient) => (
             <MatrixClientContext.Provider value={client}>
-                <ScopedRoomContextProvider {...roomContext}>
-                    <SendMessageComposer {...defaultProps} {...props} />
+                <ScopedRoomContextProvider room={mockRoom} {...roomContext}>
+                    <RoomUploadContextProvider>
+                        <SendMessageComposer {...defaultProps} {...props} />
+                    </RoomUploadContextProvider>
                 </ScopedRoomContextProvider>
             </MatrixClientContext.Provider>
         );
@@ -435,7 +438,11 @@ describe("<SendMessageComposer/>", () => {
 
         const { container } = render(
             <MatrixClientContext.Provider value={cli}>
-                <SendMessageComposer room={room} toggleStickerPickerOpen={jest.fn()} />
+                <ScopedRoomContextProvider {...({ room } as unknown as RoomContextType)}>
+                    <RoomUploadContextProvider>
+                        <SendMessageComposer room={room} toggleStickerPickerOpen={jest.fn()} />
+                    </RoomUploadContextProvider>
+                </ScopedRoomContextProvider>
             </MatrixClientContext.Provider>,
         );