Update Quickstart application-client to JakartaEE 8

Current application-client.xml are pointing to the previous JakartaEE versions. Quickstarts are known to be used as source for copy'n'paste.
Adjust config to https://www.oracle.com/webfolder/technetwork/jsc/xml/ns/javaee/index.html#8 web.xml (JakartaEE 8 https://jakarta.ee/xml/ns/jakartaee/#8 ).