int64 Precision Issues

[patrick-ogrady]

Is your feature request related to a problem? Please describe.
Some blockchain teams have noted that precision may be lost for int64 numbers in some clients (like JS) if a number greater than 2^53 is populated since JSON defines numbers as float64.

Example (BlockIdentifier): https://github.com/coinbase/rosetta-specifications/blob/439b881859b0982bb6baf34a9666db1018d419f9/models/BlockIdentifier.yaml#L22-L27

Describe the solution you'd like
Unfortunately, int64 is highest precision number type you can specify in OpenAPI (also not possible to use uint64). To remedy this issue, we would need to encode all int64 numbers as string.

Fortunately, this issue only will affect BlockIdentifer.Index and Block.Timestamp as all other "number-like" values that could come close to 2^53 are already encoded as strings (ex: Amount.Value). Operation.Index (which is also encoded in int64) shouldn't run into this issue as it is relative to the Transaction where an Operation is present in, not a global index.

[Steph380]

I'm not really sure but it is returning the sat value incorrect that all but please help fix thank you