chore: removing metamask-module-template and references

[georgewrmarshall]

Description

This PR removes all instances of @metamask/metamask-module-template from the metamask-design-system monorepo. This template was initially included during the monorepo migration as a demonstration of creating packages using the create-package script and to verify package testing configurations. Now that we have a robust set of actual packages for testing linting and configurations, this example template is no longer needed. Removing it will simplify the codebase and reduce potential confusion.

Related issues

Fixes: https://github.com/MetaMask/metamask-design-system/issues/27

Manual testing steps

1. Clone the repository and navigate to the branch.
2. Search for any remaining instances of @metamask/metamask-module-template to confirm their absence.
3. Verify the functionality of the replaced package throughout the codebase.

Screenshots/Recordings

Before

https://github.com/user-attachments/assets/f526b137-c2b1-45ca-815f-a13ee99a8ed4

After

https://github.com/user-attachments/assets/386b3a22-6a9c-4262-a6ed-e90366d89349

Pre-merge author checklist

• [x] I’ve followed MetaMask Contributor Docs.
• [x] I’ve completed the PR template to the best of my ability.
• [x] I’ve included tests if applicable.
• [x] I’ve documented my code using JSDoc format if applicable.
• [x] I’ve applied the appropriate labels to the PR (per labeling guidelines).

Pre-merge reviewer checklist

• [ ] I’ve manually tested the PR.
• [ ] I confirm this PR meets all acceptance criteria described in the ticket and that required testing evidence is provided (screenshots, recordings).