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.

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

feat(sdk): implement message wait time estimation

integration-tests: Remove superfluous nightly env tests

Fix Typo In Comment

These aren't needed anymore now that we've released the Berlin HF on Kovan and nightly has been reset.

feat(sdk): refactor into single messenger class

Extract core BSS logic into bss-core package

fix: actually allow BSS log level to be set via flags

fix: mimic BSS timestamp bug fix from #2093

crtiical -> critical

See https://github.com/ethereum-optimism/optimism/pull/2093 for more
details.

l2geth: bring back unsupported RPC methods

This was a known bug, but recently caught the reason in combing through
the new copy in the specs repo. The old hack that auto defaulted to
debug has been removed.

Removed constants from data-transport-layer

feat(sdk): implement finalize message

Depreciated unused variable from Integration tests

removed unused variable

removed-sequencer

removed-sequencer references

remove sequencer variable

removed unused variable

removed-sequencer

removed-sequencer references

remove sequencer variable

feat(sdk): introduce token bridge adapters

test(integration): withdrawing a fake L2 token

fix(bss,dtl): correctly submit and parse timestamp information for L1 to L2 txs

go/batch-submitter: Downgrade Alpine version