feat: migrate to @svgr/webpack

[austingreendev]

Description

This PR removes the babel-plugin-inline-react-svg (and svg-react-loader in styleguidist) package in favor of the @svgr/webpack webpack loader.

Detail

This move is to align ourselves more closely with create-react-app and use a more widely support inline-SVG solution. SVGR also allows us some more advanced customization than the babel plugin.

This PR includes:

• Updates to all inline-SVG usages in our markdown documentation (bulk of changes)
• Update webpack configs for build and styleguidist
• Include new SVG mock for Jest
• Remove the default SVGO preference of removing the viewBox attribute

svgoConfig: {
  plugins: {
    removeViewBox: false
  }
}

This change will allow us to have more flexibility in how we embed SVG's in the future.

Checklist

• 👌 design updates are Garden Designer approved (add the
  designer as a reviewer)
• 💅 view component styling is based on a Garden CSS
  component
• 🌐 Styleguidist demo is up-to-date (yarn start)
• ⬅️ renders as expected with reversed (RTL) direction
• 💂‍♂️ includes new unit and snapshot tests
• 📒 any new files are included in the packages src/index.js export
• 📝 tested in Chrome, Firefox, Safari, Edge, and IE11

[austingreendev]

Just added some updated SVG mocking in Jest and updated affected snapshots.

[coveralls]

Coverage remained the same at 94.751% when pulling babd9dd on agreen/svgr-webpack into 4bdc25d on master.

[ryanseddon]

Nice 💯