Iss2052 - Implement platform in maven

[jadecarino]

Why?

For galasa-dev/projectmanagement#2052

• Remove explicit versions in the galasa-maven-plugin pom.xml and draw from the platform
• Add extra dependencies into the platform
• Add signing for the platform to its build.gradle (to get ready for the 0.38.0 release)
• Add gradle.properties which provides the value of isMainOrRelease when building locally (value is provided from the GH workflows in remote builds)
• Adjust get-changed-modules-pull-request.sh script to rebuild all modules that use the platform, whenever there are changes to the platform

Testing done locally:

• Galasa repo built
• CLI repo built and generated tests ran locally
• Isolated pom.xml build locally
• API Server starts locally
• CoreManagerIVT ran locally