Touch up types

[rekmarks]

• Add full docstrings to declarations file
  • The docstrings in the JavaScript source are not picked up by TypeScript, at least in VS Code.
  • Make minor edits to source docstrings in process.
• Add typings for all send method signatures
• Use RequestArguments interface for request method
• Require opts.connectionStream param for initProvider
• Update jsonrpc property on JsonRpcRequest and JsonRpcResponse interfaces
• Update JsonRpcResponse interface to type with either result or error property
• Lint types (per our config, but without adding dependencies)
  • Basically adds spacing and semicolons

[brad-decker]

this is daf.