Bwilson/l2geth exporter

go/batch-submitter: Fix metrics server

The metrics server wasn't running because of a space between the host and port.

ops/docker: Use old directory in packages dockerfile

`Dockerfile.packages` placed build artifacts in `/optimism`, whereas all of our other Dockerfiles place build artifactrs in `/opt/optimism`. As a result, downstream consumers of the packages Dockerfile cannot use images created by our other Dockerfiles. This is a problem for the nightly environment, since it relies upon the `/opt/optimism` structure to customize container entrypoints.

This PR fixes the problem by having `Dockerfile.packages` put build artifacts in `/opt/optimism` like everything else.

Version Packages

feat: tests for CrossChainProvider constructor and getMessagesByTransaction

Develop -> Master

Version Packages

feat: add telemetry to go batch-submitter

feat: add SDK contract utils and corresponding tests

Force proxyd build

Develop -> Master Release PR

Add nightly builds via CircleCI

Metadata:

- Fixes ENG-1660

Proxyd should use json logging

Version Packages

feat: surface miner nonce too high errors

This commit exposes the ErrNonceTooHigh at the execution level to
external users. Previously the error was mapped to ErrNonceTooLow to
match the mempool behavior. As this is a new error, and one not
currently exposed in L1, this could be a breaking change for some
applications depending on how the error messages are parsed.

Develop -> Master PR

feat: add v0 go batch submitter and gh actions integration

For some reason the log level environment variables aren't being picked
up, and neither is the default value for the flag being applied to the
final binary when run in docker. Remove this commit once a fix is
established.