AssetManager 0.5.5.56

Uses the same transparent image presentation in asset and category tables.
Asset and category edit forms now use the same immediate image-removal button workflow.
Replacing or removing a category image removes the superseded upload file.
Table resize handles are kept inside each header cell and pointer tracking is handled globally, improving column resizing on management tables such as Categories, Translations, Status Values and Fields.
Dashboard/category images use object-fit: contain so the complete image remains visible.