Add HATEOAS links to aggregator API endpoings

## Why
Adding HATEOAS style links to the aggregator API would allow it to be self describing and allow for dynamic navigation based on previous responses.

## What
Involves adding a "links" section to the HTTP Responses that document the available navigation endpoings
https://en.wikipedia.org/wiki/HATEOAS

For example the following api endpoint has HATEOAS links that describe the navigation related to a wallet
https://api.canadastakes.ca/preview/api/wallets/addr_test1vqeux7xwusdju9dvsj8h7mca9aup2k439kfmwy773xxc2hcu7zy99

For example where this could be useful is the following endpoints that would allow for additional navigation components to be available.
https://aggregator.release-mainnet.api.mithril.network/aggregator
https://aggregator.release-mainnet.api.mithril.network/aggregator/artifact