[Theme Checks] Added in a check for theme block settings validation

[AribaRajput]

What are you adding in this PR?

First part of #602

Adding in a theme check for checking theme blocks for valid preset setting keys. The preset setting keys (and the presets of any theme block preset settings) must match the settings keys configured in either the preset settings or the nested theme block settings.

Docs PR: https://github.com/Shopify/shopify-dev/pull/51243

What's next? Any followup issues?

The next issue is to add the exact same type of theme check for section files, just with more coverage.

What did you learn?

A lot about presets, sections and theme blocks and how they are configured. That was the trickiest part of all of this (managing the types, knowing how to grab nested information, etc).

Before you deploy

• This PR includes a new checks or changes the configuration of a check
  • I included a minor bump changeset
  • It's in the allChecks array in src/checks/index.ts
  • I ran yarn build and committed the updated configuration files
    • If applicable, I've updated the theme-app-extension.yml config

• I included a minor bump changeset
• My feature is backward compatible

• I included a patch bump changeset

[charlespwd]

Position information can't be ignored for this check. We'll probably need to rewrite it and iterate over each blocks separately rather than push all of them in the same bucket.