[api] Network Endpoint Use Current Fee Values
Resolves #1683 (closed). This updates the network endpoint to return current fees instead of what they will become to give UIs and exchanges a target they can use for seamless transition. Deployed to https://thornode.dev.ninerealms.com for comparison:
diff <(http https://thornode.ninerealms.com/thorchain/network height==12549527) <(http https://thornode.dev.ninerealms.com/thorchain/network height==12549527)
8,9c8,9
< "native_outbound_fee_rune": "1300000",
< "native_tx_fee_rune": "1300000",
---
> "native_outbound_fee_rune": "2000000",
> "native_tx_fee_rune": "2000000",
11,12c11,12
< "tns_fee_per_block_rune": "13",
< "tns_register_fee_rune": "680000000",
---
> "tns_fee_per_block_rune": "20",
> "tns_register_fee_rune": "1000000000",