Add preconnect and preload for webfonts to zanata-frontend

Description

Improvement to usage of webfonts in frontend

Add preconnect to frontend for SourceSansPro
https://www.cdnplanet.com/blog/faster-google-webfonts-preconnect/
Add preload to frontend for Zanata.woff (icon font)
https://developers.google.com/web/fundamentals/performance/optimizing-content-efficiency/webfont-optimization#preload_your_webfont_resources

Ready for Release
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Assignee

Kathryn Gough

Reporter

Kathryn Gough

Tested Version/s

None