Move tests to separate Gradle module.

build.gradle

src/main/java/org/jastadd/ros2rag/compiler/Compiler.java

src/test/.gitignore

src/test/01-input/example/Example.jadd

src/test/01-input/example/Example.relast

src/test/01-input/example/Example.ros2rag

src/test/01-input/example/linkstate.proto

src/test/01-input/example/robotconfig.proto

src/test/java/org/jastadd/ros2rag/tests/ExampleTest.java

src/test/java/org/jastadd/ros2rag/tests/RosToRagTest.java

test.build.gradle