feat: Start creating separate metadata module

[wayfarer3130]

Context

Create a separate metadata library for all the metadata providers so that the metadata can be loaded for uses other than for rendering.

Changes & Results

Create new @cornerstonejs/metadata library and test it in the localAdvanced sample by clicking on "new metadata"

Testing

Checklist

PR

• [] My Pull Request title is descriptive, accurate and follows the
  semantic-release format and guidelines.

Code

• [] My code has been well-documented (function documentation, inline comments,
  etc.)

Public Documentation Updates

• [] The documentation page has been updated as necessary for any public API
  additions or removals.

Tested Environment

• [] "OS:
• [] "Node version:
• [] "Browser: