l2geth: Add commands to initialize from a URL, and dump the current chainstate

This PR adds two commands to l2geth:

- `geth init <url> <genesisHash>`, which will download a remote genesis JSON file, compare its hash to the one specified on the CLI, then reinitialize the chain config.
- `geth dump-chain-cfg`, which will dump the current chain config to stdout.

These commands will make it easier for us to adopt the upcoming gas schedule hardfork.

Fixes: ENG-1906

Add integration tests to test the hardfork logic

The hardfork block will need to be determined
and the genesis json file will need to be
recreated. This will by default set the
height to 0 so that the development
networks start with berlin activated.

These scripts can be used to set up a
local development environment to test
out sending transactions against

If the `DEVELOPMENT` env var is set, then
the initial genesis state will include funds
for the signer address. This prevents the
need to deposit funds or manually edit the
genesis json file.

Be sure to switch to using the new rules
at a specific height

The implementation is copied from upstream
https://github.com/ethereum/go-ethereum/commit/a5669ae292274d3b0a223cda07ebe64f943bded4

fix

integration-tests: Changes to make it work with live networks again

chore(deps): bump trim-off-newlines from 1.0.1 to 1.0.3

l2geth: fix monotonicity logging bug

feat: add confirmation depth awareness to txmgr

go/proxyd: Cache block-dependent RPCs