Bugfix/cartoee orientation

[KMarkert]

cartoee was producing plots with imagery being oriented wrongly, see #177. This was due to data being requested without a fixed spatial reference. This PR fixes the bug by adding the crs parameter when requesting data from EE.

It should be noted that the only CRS support for EE requests as of now is WGS84 (EPSG:4326). This is because it is the only CRS directly transferable to a cartopy.crs projection. This forces all of the EE computations in WGS84 which is not so ideal but allows the reprojections to cartopy crs be done locally with correct plotting.

[giswqs]

/ok-to-test

[eselrodrigo]

The solution proposed didn't work for me, I think it's not a coordinates system problem but a matrix mirroring problem in this part of the "add_layer" module inside cartoee.py:

image = np.array(Image.open(BytesIO(response.content)))

if image.shape[-1] == 2:
    image = np.concatenate(
        [np.repeat(image[:, :, 0:1], 3, axis=2), image[:, :, -1:]], axis=2
    )

for witch the solution was adding a left right flip to the final image (np.fliplr(np.squeeze(image))),

ax.imshow(
    np.fliplr(np.squeeze(image)),
    extent=view_extent,
    origin="upper",
    transform=ccrs.PlateCarree(),
)

Sorry I didn't have time to study the exact part of the matrix array that originates the problem.