Adds step to upload and download build artifacts

[dingfeli]

Premise

CI step Build with maven has been failing with the following message:

Error:  Failed to execute goal org.eclipse.tycho:tycho-packaging-plugin:4.0.8:package-plugin (default-package-plugin) on project amazon-q-eclipse: /home/runner/work/amazon-q-eclipse/amazon-q-eclipse/plugin/build.properties: bin.includes value(s) [webview/build/] do not match any files. -> [Help 1]
Error:  
Error:  To see the full stack trace of the errors, re-run Maven with the -e switch.
Error:  Re-run Maven using the -X switch to enable full debug logging.
Error:  
Error:  For more information about the errors and possible solutions, please read the following articles:
Error:  [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException
Error:  
Error:  After correcting the problems, you can resume the build with the command
Error:    mvn <args> -rf :amazon-q-eclipse
Error: Process completed with exit code 1.

Changes:

• Added a step to upload the build artifact after webview npm install & npm run webpack.
• Added a step to download the aforementioned build artifacts prior to step Build with maven.

Test

CI passes.

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[breedloj]

Closing as we have resolved this issue through fixes to the Maven build to directly build the NPM components in the project.