Revert the part that limits caption width on unresized images

We have a plethora of different combinations of images and captions.

Floated images with captions, non floated images with captions, small images with captions, etc. etc.

In general we use a `display: table;` trick to get the caption to size itself according to the image. However if an unfloated image follows a floated image, this means the unfloated image can size itself down to "fit in the available space", which is not what we want. So for now, if you upload a small image and _don't_ float it, a wide caption will be as centered as the block itself.

This might be worth revisiting, but at this point I'd like to look at that separately from this PR which is already big.

packages/block-library/src/image/editor.scss

@@ -136,7 +136,7 @@
 }
 
 // This is similar to above but for resized unfloated images only, where the markup is different.
-[data-type="core/image"] .editor-block-list__block-edit figure:not(.alignfull):not(.alignwide) {
+[data-type="core/image"] .editor-block-list__block-edit figure.is-resized {
 	margin: 0;
 	display: table;
 

packages/block-library/src/image/style.scss

@@ -45,15 +45,3 @@
 		@include caption-style();
 	}
 }
-
-// Resized images that are not floated, so they need the caption trick too.
-// These apply the .wp-block-image class on the <figure> element itself.
-figure.wp-block-image {
-	display: table;
-	margin: 0;
-
-	> figcaption {
-		display: table-caption;
-		caption-side: bottom;
-	}
-}