[ZEPPELIN-6466] Improve RepositorySystemFactory error reporting

[vividbaek]

What is this PR for?

Replace printStackTrace() in RepositorySystemFactory with SLF4J error logging so service creation failures are handled through the configured logging framework.

Also add a meaningful message to the RuntimeException thrown when locator.getService(RepositorySystem.class) returns null.

What type of PR is it?

Improvement

Todos

• Replace printStackTrace() with SLF4J logging
• Add a descriptive exception message
• Build the shaded interpreter JAR

What is the Jira issue?

https://issues.apache.org/jira/browse/ZEPPELIN-6466

How should this be tested?

The following commands were run successfully:

• ./mvnw test -pl zeppelin-interpreter --am
  • 126 tests passed
• ./mvnw clean package -pl zeppelin-interpreter,zeppelin-interpreter-shaded -DskipTests
  • Build succeeded

Screenshots (if appropriate)

N/A

Questions:

• Does the license files need to update? No
• Is there breaking changes for older versions? No
• Does this needs documentation? No