Move expectation files

What does this MR do?

This MR replaces main directory names with default in the qa directory. It also moves all "orphaned" gl-dependency-scanning-report.json expectation files to subdirs, for example:

Instead of:

qa/expect/java-gradle-multimodules/gl-dependency-scanning-report.json
qa/expect/java-gradle/main/cyclonedx-maven-gradle.json

We now have:

qa/expect/java-gradle/multimodules/gl-dependency-scanning-report.json
qa/expect/java-gradle/default/cyclonedx-maven-gradle.json

See this discussion for more details.

What are the relevant issue numbers?

gitlab-org/gitlab#293758 (closed)

Does this MR meet the acceptance criteria?

• [-] Changelog entry added
• Documentation created/updated for GitLab EE, if necessary
• Documentation created/updated for this project, if necessary
• Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• Job definition updated, if necessary
  • Auto-DevOps template
  • Job definition example
  • CI Templates
• Conforms to the code review guidelines
• Conforms to the Go guidelines
• Security reports checked/validated by reviewer