chore: Make `image` field obsolete in Website Item (redundant)

- Delete Image field and set `website_image` as form's image field for uploads
- Remove instances of `image` field access via Website Item
- Item -> Web Item via Desk: Map Item's `image` to Web Item's `website_image`
- Item -> Web Item via patch: `website_image` will be mapped with thumbnail
- Remove magic that auto-sets `website_image` from `image` in Website Item
diff --git a/erpnext/templates/generators/item/item_image.html b/erpnext/templates/generators/item/item_image.html
index 930bb7a..e1bb3b9 100644
--- a/erpnext/templates/generators/item/item_image.html
+++ b/erpnext/templates/generators/item/item_image.html
@@ -24,7 +24,7 @@
 			})
 		</script>
 	{% else %}
-		{{ product_image(doc.website_image or doc.image, alt=doc.website_image_alt or doc.item_name) }}
+		{{ product_image(doc.website_image, alt=doc.website_image_alt or doc.item_name) }}
 	{% endif %}
 
 	<!-- Simple image preview -->
diff --git a/erpnext/templates/includes/macros.html b/erpnext/templates/includes/macros.html
index fb4cecf..3e20e50 100644
--- a/erpnext/templates/includes/macros.html
+++ b/erpnext/templates/includes/macros.html
@@ -74,7 +74,7 @@
 {%- set col_size = 3 if is_full_width else 4 -%}
 {%- set title = item.web_item_name or item.item_name or item.item_code -%}
 {%- set title = title[:50] + "..." if title|len > 50 else title -%}
-{%- set image = item.website_image or item.image -%}
+{%- set image = item.website_image -%}
 {%- set description = item.website_description or item.description-%}
 
 {% if is_featured %}