Neon-js light wallet wrapper

[slipo]

Description

This adds a wrapper class over neon-js to provide light wallet support. A few notes:

Because the required functionality for a light wallet isn't really supported by core neo nodes and requires accessing CoZ sites running NeonDB, I do believe @lllwvlvwlll's guidance was right and we should offload this integration to neon-js.

Local storage wallet support can be built on top of this as an alternation data access method. We have transaction history and balance support already from local data. One open question is in what format to we return the data. I would argue we should return data the same as neon-js. I'm doing this for now.

Some of the methods used by neon-js return or use as parameters internal classes such as "Transactions" ... we don't quite have the equivalent right now and it would be a bit of work to implement them. What to do here should also be discussed.

Motivation and Context

Wallet support: #78
Integrate neon-js: #101

How Has This Been Tested?

For now, there's an example script that shows how it works.

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[rockacola]

I see your neon-js reference and usage, however you may be missing package.json updates for your PR.

[lllwvlvwlll]

@slipo Could you add test coverage?

[snowypowers]

just saw this so gonna drop some comments:

1. I am leaning towards dropping support for all transactional methods in neonDB file. So stuff like doTransferToken, doClaimAllGas and doSendAsset will be deprecated in the near future. The reason is that they dont belong there anymore. neonDB should be an API layer that wraps the external data for neonjs to utilise. Replacements can be found in api/core instead.

2. I thought this was for NEP6 Wallet lol. Confusing to have similar names but differing functions.

3. Looking forward to a neoJS file in the future. It should be structured similarly to how neonDB or neoscan is structured now so that neonjs can choose which provider to use and drop it in.

[lllwvlvwlll]

@snowypowers I think we can merge this for now and track against changes to neon-js and neondb. Eventually, I think project will actually invert with there being neo-js nodes running which neon-js interfaces with.

[lllwvlvwlll]

Great work. Sorry it took so long to get in!