NIFI-11034: Restore image viewer to nifi-assembly

[mattyb149]

Summary

NIFI-11034 This PR creates a nifi-image-viewer-nar and moves the image viewer WAR from the nifi-media-nar to the nifi-image-viewer-nar. The former is not included by default in the assembly, but this PR adds the latter to the assembly so the Image Viewer is always available to the UI. The new NAR is only 16K in size so there should be no concern over the increased footprint.

Tracking

Please complete the following tracking steps prior to pull request creation.

Issue Tracking

• Apache NiFi Jira issue created

Pull Request Tracking

• Pull Request title starts with Apache NiFi Jira issue number, such as NIFI-00000
• Pull Request commit message starts with Apache NiFi Jira issue number, as such NIFI-00000

Pull Request Formatting

• Pull Request based on current revision of the main branch
• Pull Request refers to a feature branch with one commit containing changes

Verification

Please indicate the verification steps performed prior to pull request creation.

Build

• Build completed using mvn clean install -P contrib-check
  • JDK 11
  • JDK 17

Licensing

• New dependencies are compatible with the Apache License 2.0 according to the License Policy
• New dependencies are documented in applicable LICENSE and NOTICE files

Documentation

• Documentation formatting appears as expected in rendered files

[mattyb149]

@MikeThomsen did you merge this to both branches (main and support-1.x)? Can you update the Fix Version in the Jira to the actual versions (we use the .latest to indicate which lines they should land on. Thank you!