Utxo and PoolInfo amounts to string + axios update + new endpoint

[AlexDochioiu]

Hey, the changes are:

• updated the interfaces and following APIs to return the amounts as string:
• added addresses/cred/utxos endpoint
• Updated axios to ^1.6.0 to mitigate vulnerability in ^1.5.0 (reported in yarn audit)

The updated APIs are:

GET /accounts/{stake_addr}/assets

GET /addresses/{address}/utxos POST /addresses/utxos GET /addresses/cred/{credential}/utxos POST /addresses/cred/utxos (NEW ENDPOINT)

GET /pools/{pool_id}/info

POST /transactions/outputs

[AlexDochioiu]

@Vardominator