upgrade element bridge to use falafel's new REST API

[spypsy]

Description

This PR is adding new APIs that will replace graphQL functionality.
Updating logic here to use new APIs. Once this is merged & released, we can remove graphQL altogether from falafel

Setting this as "draft" until new Falafel APIs are released

Checklist:

• I have reviewed my diff in github, line by line.
• Every change is related to the PR description.
• There are no unexpected formatting changes, or superfluous debug logs.
• The branch has been rebased against the head of its merge target.
• I'm happy for the PR to be merged at the reviewers next convenience.
• NatSpec documentation of all the non-test functions is present and is complete.
• Continuous integration (CI) passes.
• Command forge coverage --match-contract MyContract returns 100% line coverage.
• All the possible reverts are tested.

[benesjan]

@spypsy I just merged my PR which makes the contract tests pass. Please rebase on master. It will hopefully make the whole CI pass.