Brainstorm & document the interfaces for new output types & transactions

[laumair]

Description

We need to brainstorm and also document ideas for interfaces that would allow users to access information from the library for new output types & transactions.

Motivation

It is not 100% clear how the wallet library should abstract away (or expose) new features enabled by the introduction of new output types. For instance, some questions that can be answered are:

• As a library user, would I need to access all addresses & outputs? If yes, how should the interface look like?
• As a library user, if I need to access outputs, how should I do it? By type, by timestamps or by pagination? This is also related to Research for better scaling solutions around transactions & outputs #806 so it can be covered as part of it;
• If I am an exchange and want to use the new output types, what would I be expecting from the wallet library?
• If I am a wallet application and want to use the new output types, what would I be expecting from the wallet library?

I created this template which we can follow to document these ideas.

Important: Firefly team brainstormed use cases around new tokenisation types, so we should also get some ideas from their brainstorming sessions. They documented their ideas.