Fix the giant icon problem in the warning messages

[eason9487]

Changes proposed in this Pull Request:

This problem was discovered in #527.

Root cause

Libraries depend on a different version of @wordpress/icons, causing the react component instance checking icon.type === SVG to get false result.

https://github.com/WordPress/gutenberg/blob/%40wordpress/components%4012.0.8/packages/components/src/icon/index.js#L41-L50

Solution

Upgrade @wordpress/icons to the same version used in @wordpress/components.

Screenshots:

Detailed test instructions:

1. npm install and restart dev build npm start
2. Set the store location to “South Sudan” in WooCommerce → Settings
3. Head to the Get Started page and the external link icon should be displayed with a proper size.

[tomalec]

Tested locally, LGTM