Request: Document "Sponsor Transaction" service endpoints

[sambacha]

https://docs.tatum.io/reference/precalculategaspumpaddresses

Action Description	Method
Precalculate gas pump addresses	POST
Activate gas pump addresses	POST
Get the results of the address activation transaction	GET
Check whether the gas pump address with a specified index is activated	GET
Transfer an asset from a gas pump address	POST
Transfer multiple assets from a gas pump address	POST
Approve the transfer of an asset from a gas pump address	POST
Generate a gas pump wallet address	POST
Generate a custodial wallet address	POST
Get the custodial wallet address from the transaction	GET