NIFI-15963 Migrate ErrorBanner usages to Banner

[venkateshwaracholan]

Summary

NIFI-15963

Replace remaining ErrorBanner usages with the shared Banner component and remove the deprecated ErrorBanner implementation.

Migrate banner usages in NiFi and NiFi Registry
Remove the ErrorBanner component and export from @nifi/shared
Remove unused imports
Align with the existing wizard-context-banner pattern

Banner is built on StatusBanner and supports the inputs used by existing call sites (messages, allowDismiss, and dismiss).

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 contains commits signed with a registered key indicating Verified status

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 ./mvnw clean install -P contrib-check
  • JDK 21
  • JDK 25

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

[venkateshwaracholan]

Recreating this PR after accidentally deleting my fork, which closed the original PR.

Related: #11308