Update image with newer version

## Bug description

In the editor mode of the DevPortal you can upload and delete images at the bar on the left.
One thing that is missing is that images should be replaced/updated with newer version of an image.

Here is a proposal from my side how it could look like:

If one should use this feature all image elements containing the old image should automatically be updated and replaced.
This should also be possible in the context menu of the image settings.

If this isn't possible then it will become a problem if the DevPortal has many pages with many images, because if one deletes an image and doesn't change it at the target location issues occur. Therefor in the end if will mess up the library and decrease the migration speed.

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@AnRei123

Start by tracing the DevPortal editor's existing image upload and delete flows, then inspect the image settings context menu. Define how replacing an image should update every image element that references the old image, and verify that deleting or replacing images does not leave broken references across pages.

Written by the indexing model from the issue text.