[SuperNode program] task: update supernode url.

[AnthonyLaw]

What was the issue?

• supernode URL is no longer valid, it needs to replace the new URL.

What's the fix?

• removed getGeolocation because it's an unused method.
• add getNodes method in superNodeProgram service.
• replace supernode's getNodes in normal and multisig's ImportanceTransfer controller.
• add unit test.

[cryptoBeliever]

@AnthonyLaw I don't see any issue with wallet for both multisig and single harvesting view :+1: