There is a plugin for Sigil,
InsertImageSVG, that'll
mostly do the trick. It allows you to add and/or insert images that are either external or in the ePub images folder. Once you have the images identified in the plugin you just have to select each individual image and click on the "insert" button. When you've done that for each image click on the "close" button and all the images will appear on their own page with an SVG wrapper.
I use the "insert before" option and select the last page in the book, then select the images in the order I want them to appear in the ePub.
I think the author is working on a way to import multiple images at a time, but for now this is a fairly simple procedure.
edit: while this is certainly not a "push the button once and everything is done for me automatically" it is quite simple and you can do 100 images in about 2 minutes...literally... (and I mean
literally in the original definition of the word not the "figuratively" that literally replaced "literally" in the dictionary)