Update mongo-express version to v1.0.2

Starting one of the containerlab environments and accessing mongodb-express with version v0.54.0 resulted in the error message:

Turn on admin in config.js to view server stats!

Description

This MR fixes this issue by updating the version of the docker image to v1.0.2 and setting the correct environment variables for the container.

Related Issue

#358

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.