Tomcat module cleanup

[pepness]

Cleanup:

• Remove unnecessary if/return statement
• Add missing braces
• Add missing @Override annotations
• Use diamond inference
• Use try-with-resources
• Use StandardCharsets instead of a String
• String concatenation in logger
• Use multi-catch and a more specific catch
• Improve Collection.toArray
• Length one String literal in String.indexOf
• Looks for string concatenation in StringBuilder
• Replace StringBuffer with StringBuilder when not necessary

Testing:

• Full build done
• Verify successful execution of libraries and licenses Ant test
• Verify successful execution of Sigtests
• Verify successful execution of commit-validation
• Verify successful execution of rat-exclusions
• Verify successful execution of enterprise.tomcat5 unit tests
• Started NetBeans and ensure the log didn't have any ERROR or new WARNINGS

After this, I plan to improve Tomcat/TomEE support for Jakarta EE 9/9.1

[mbien]

upstream commits show up in this PR now. This usually happens when they are pulled from a different branch (maybe delivery?) without setting the --rebase flag. Its probably better to move your commits on a fresh copy of master before integration.