Add a default goal to Maven

[kinow]

Description

Just so devs don't need to remember which goal to use 👍 simply run mvn or ./mvnw

Motivation and Context

No need to remember to type a Maven goal, and we can change it later too without impacting devs (e.g. add checkstyle or other linters, etc)

How Has This Been Tested?

Locally.

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 change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[mr-c]

Thanks!