feat(sdk): allow withdrawals or deposits to target

This commit updates the SDK to add support for withdrawing or depositing
to a target address (as opposed to simply depositing or withdrawing to
yourself).

feat(itests): remove Watcher from fundUser

This commit removes the deprecated Watcher class from the fundUser
function in favor of using the CrossChainMessenger class from the new
Optimism SDK. This is part of a series of commits that are designed to
eventually remove the Watcher entirely from the integration tests (and
then from the entire repository).

feat: use SDK for bridge integration tests

Version Packages

Develop -> Master PR

maintenance: decrease geth diff

Remove some unused code

dtl: handle errors in context api

develop => master

Version Packages

develop => master

Both `GET /eth/context/latest` and `GET /eth/context/blocknumber/:number`
rely on fetching a remote block to pull the timestamp, blocknumber and
blockhash from. If the fetched block is not found, then properties on
`null` will be attempted to be accessed which will result in a runtime
error. This commit adds handling for this case to prevent that kind of
bug.

fix: correctly export SDK

master => develop

Version Packages

merge develop into master

fix(sdk): updated flaky test

fix: have sdk use ethers peer dep

build(deps): bump simple-get from 2.8.1 to 2.8.2

l2geth: update readme

maintenance: update ethers deps

feat: SDK beta release

Bumps [simple-get](https://github.com/feross/simple-get) from 2.8.1 to 2.8.2.
- [Release notes](https://github.com/feross/simple-get/releases)
- [Commits](https://github.com/feross/simple-get/compare/v2.8.1...v2.8.2)

---
updated-dependencies:
- dependency-name: simple-get
  dependency-type: indirect
...
Signed-off-by: dependabot[bot] <support@github.com>

feat(sdk): start using sdk in integration tests