The Font Awesome font wasn't loaded correctly in the Storybook build.
Unlike our other fonts, Font Awesome is copied from `node_modules` at
build-time rather than being saved directly in `app/fonts`.
The `copy-webpack-plugin` plugin is now used in the Storybook webpack
build to copy the fonts explicitly from `node_modules` into the build
output directory. The font now seems to load correctly in Storybook.
Various SVGs were being imported directly in components using Webpack
loaders. This was done to get these components to work correctly in
storybook, which uses Webpack. However we don't use Webpack for our
actual build system, so these components would fail when you attempted
to use them.
Instead the storybook script has been updated to use the `--static-dir`
flag, which allows specifying a directory of files to serve statically.
The `app` directory is served statically, so all of the relative URLs
we use in practice to reference fonts and images should just work.
The storybook build command has been updated to use the same flag.
Unfortunately this also means that the uncompiled background code is
now included in the build as well, because it's alongside our static
files. This shouldn't have any impact upon the build though.
The use of this `static-dir` option as made much of the existing
storybook Webpack configuration unnecessary, so it has been reduced to
just the essential steps.
* Adds notification icon circles and associated storybook stories
* Fix image paths in circle-icon.stories and message-circle-icon.component
* Code improvements for icon circles PR: remove additional z-index, make iconSource required
* Use component story format in circle-icon.stories and message-circle-icon.stories
* Remove success and info circle icons, as not presently needed
* Rename message-circle-icon to alert-circle-icon
* Small code fix ups for alert-circle-icons
