Eigenda memstore

[gianbelinche]

What ❔

This PR adds memstore implementation for eigenda proxy

Why ❔

Checklist

• PR title corresponds to the body of PR (we generate changelog entries from PRs).
• Tests for the changes have been added / updated.
• Documentation comments have been added / updated.
• Code has been formatted via zk_supervisor fmt and zk_supervisor lint.

[github-actions]

Hey there! 👋🏼

We require pull request titles to follow the Conventional Commits specification and it looks like your proposed title needs to be adjusted.
Examples of valid PR titles:

• feat(eth_sender): Support new transaction type
• fix(state_keeper): Correctly handle edge case
• ci: Add new workflow for linting

Details:

No release type found in pull request title "Eigenda memstore". Add a prefix to indicate what kind of release this pull request corresponds to. For reference, see https://www.conventionalcommits.org/

Available types:
 - feat: A new feature
 - fix: A bug fix
 - docs: Documentation only changes
 - style: Changes that do not affect the meaning of the code (white-space, formatting, missing semi-colons, etc)
 - refactor: A code change that neither fixes a bug nor adds a feature
 - perf: A code change that improves performance
 - test: Adding missing tests or correcting existing tests
 - build: Changes that affect the build system or external dependencies (example scopes: gulp, broccoli, npm)
 - ci: Changes to our CI configuration files and scripts (example scopes: Travis, Circle, BrowserStack, SauceLabs)
 - chore: Other changes that don't modify src or test files
 - revert: Reverts a previous commit

[juan518munoz]

LGTM

The put & get method might be movable into a interface in a later revision.