Adds @storybook/react and associated npm modules
- Updates .babelrc plugins to use the right plugins for object spread and class properties
- Modifies webpack config to include parsing stories in addition to components
- Adds a story for Alert + adds style for info alert
- Adds story to BtnWithLoading component + Fixes BtnWithLoading component (prop types)
- Adds story for SortableStickyGrid component
- Modifies bootstrap_4_patch scss file to export mixin to be reused in storybook context
- Adds types for @storybook/react
- Adds pom build step to build storybook
