Swagger-like UI for calling services

[VanishMax]

Right now we use Buf studio to test data from the services. The problem of Buf studio is that it only allows to test public methods like AssetMetadataById or CurrentGasPrices but it cannot query private services to, for example, access the balances of the user accounts.

The proposed idea is to create a Swagger-like UI with 'Connect to Prax' button. It should connect to the wallet api and display the list of available services. This list should be dynamically parsed from the generated protobuf message types instead of hard-coding the list of available services and their arguments.

It should be possible to call any service with some arguments and see the result in prettified JSON.

This app could potentially live in the apps/ directory or in the Penumbra Guide repo since it allows importing React components.