Gracefully handle malform token's name

[pdp2121]

Currency name with less than or equal to 3 characters issuing as a hex was label with prefix "Fake" (see https://github.com/ripple/explorer/pull/1131). We should handle this more gracefully by:

• For token, add a warning sign instead of the Fake prefix (avoid changing token's intended name)
• For oracle, since price feed is just data, not actual tokens that are transactable, remove the prefix.

Important: Make sure any token with name "XRP" DOES NOT have the X icon in UX