Finish FontAwesome deprecation

[viktorrusakov]

We started deprecation of font-awesome a while ago, but didn't complete it as it would introduce breaking changes for the consumers. With design tokens release it seems like it's a good opportunity to finish this deprecation process as v21 of Paragon will have a lot of breaking changes anyway (e.g., we finally removed all deprecated components).

AC

Beta Give feedback

1. Completely remove font-awesome usage in the alpha branch

[adamstankiewicz]

Currently still used in IconButton (default icon is from font-awesome). Would have been a breaking change so we originally deferred.

We did add console.error to warn consumers of the deprecation to encourage them to migrate off.

[PKulkoRaccoonGang]

PR: #2327