test(verifier-client): import ApiClient dynamically

[outSH]

• Import ApiClient from connector packages dynamically.
• Make getVerifier and getValidatorApiClient methods async to allow
  use of dynamic ESM import in the future.
• Make connector dependencies of verifier-client optional. User must manually
  install connector package they use to satisfy an optional peer dependency.
  Connectors are still needed for building (i.e. devDependencies).
• Cleanup dependencies of verifier-client
• Use async verifier factory methods in tests and sample apps.

Depends on #2904

Pull Request Requirements

• Rebased onto upstream/main branch and squashed into single commit to help maintainers review it more efficient and to avoid spaghetti git commit graphs that obfuscate which commit did exactly what change, when and, why.
• Have git sign off at the end of commit message to avoid being marked red. You can add -s flag when using git commit command. You may refer to this link for more information.
• Follow the Commit Linting specification. You may refer to this link for more information.

Character Limit

• Pull Request Title and Commit Subject must not exceed 72 characters (including spaces and special characters).
• Commit Message per line must not exceed 80 characters (including spaces and special characters).

A Must Read for Beginners
For rebasing and squashing, here's a must read guide for beginners.

[petermetz]

LGTM

[izuru0]

LGTM

[github-actions]

This PR/issue depends on:

• test(cactus-test-verifier-client): replace socketio connector with eth openapi #2904
  By Dependent Issues (🤖). Happy coding!