refactor: javax.servlet --> jakarta.servlet

[jo-elimu]

Warning

Cannot be merged until we find a fix for the Spring Security problem.

Issue Number

• Resolves Change to Jakarta EE Namespace #1691

Purpose

• Change to Jakarta EE Namespace so that we can upgrade to Jetty 11 (Servlet 5, JSP 3.0), Spring 6, Spring Security 6, Hibernate 6.

Technical Details

• These changes only work partially:
  • Spring Security causes redirect to /sign-on, and the page is not displayed.
  • 8 failing unit tests when running mvn clean test due to NoClassDefFound jakarta/servlet/ServletConnection

Testing Instructions

• mvn jetty:run
• mvn clean test

Screenshots

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