Redefine galleryApi endpoint by introducing library for SignalR testing

[JanSafronov]

Redefine getGalleryPhotos endpoint of galleryApi by coalescing HubConnectionBuilder and useCypressSignalRMock (They build a hub connection) from Cypress testing library.

Whenever in testing mode, useCypressSignalRMock will not be null and hence a mocked SignalR hub will be instantiated for testing purposes.

Implicity this is coded as

const socket = MockHubConnectionBuild("testhub", {
    enableForVitest: true,
}) ?? new HubConnectionBuilder().withUrl(`${import.meta.env.VITE_GALLERY_SERVICE_URL}/hubs/gallery?galleryId=${galleryId}`).build();

This inherits/includes feature 1 branch given in #87

[JanSafronov]

@Olszewskidev This allow to run integration tests for UI packages when hub connection is needed..

[Olszewskidev]

Thanks for your changes and adjustments. LensUp takes part in 100 Commits challange (Polish competitions) - https://100commitow.pl/

I will check your PR's after this challange (we are at the end)
Btw you can give me a star on github if you want. The number of stars affects the competition result.

Thanks!