feat(fonts): add google font support via flag

[tw15egan]

Closes #10353

Adds in out-of-the-box support for Google fonts by enabling the $use-google-fonts flag. It has been turned on by default for testing purposes.

If turned on, it will create the src field from google data, rather than resolve to the installed plex package.

Changelog

New

• $use-google-fonts flag, which if enabled will provide font files directly from the Google static server rather than the @ibm/plex package itself.
• Map of all the google data in @styles/scss/fonts/_src.scss

Testing / Reviewing

First, navigate to the IBM Plex story in the carbon-react storybook. Then, in dev tools, go to the Network tab, hit record, and do a hard refresh. The woff files should resolve to Google servers. If testing locally, flip the flag to false and see that the path is now set to the locally installed font files.

Before merging the flag should be set to false by default.

[netlify]

✔️ Deploy Preview for carbon-react-next ready!

🔨 Explore the source changes: 0b54c93

🔍 Inspect the deploy log: https://app.netlify.com/sites/carbon-react-next/deploys/61e1bf09f6e411000736af4c

😎 Browse the preview: https://deploy-preview-10393--carbon-react-next.netlify.app

[netlify]

✔️ Deploy Preview for carbon-elements ready!

🔨 Explore the source changes: 0b54c93

🔍 Inspect the deploy log: https://app.netlify.com/sites/carbon-elements/deploys/61e1bf09eb25010008c78ba4

😎 Browse the preview: https://deploy-preview-10393--carbon-elements.netlify.app

[netlify]

✔️ Deploy Preview for carbon-components-react ready!
Built without sensitive environment variables

🔨 Explore the source changes: 0b54c93

🔍 Inspect the deploy log: https://app.netlify.com/sites/carbon-components-react/deploys/61e1bf09d273f50008cdbee8

😎 Browse the preview: https://deploy-preview-10393--carbon-components-react.netlify.app

[abbeyhrt]

Looks good to me! Pulls in fonts from google as expected 👍

[jnm2377]

🔥 great work on this!