Implement cache management

[Kashuab]

We should support the cache policies that mst-gql supports:

• "cache-first": Use cache if available, avoid network request if possible
• "cache-only": Use cache if available, or error if this request was not made before
• "cache-and-network": Use cache, but still send request and update cache in the background
• "network-only": Skip cache, but cache the result
• "no-cache": Skip cache, and don't cache the response either

[Kashuab]

Done. Implemented DepotGQLClient which acts as a wrapper around GraphQLClient from graphql-request, which adds a cache layer that integrates with the RootStore.

See docs: https://mobx-depot.dev/docs/caching