Javadoc Technical Debt - #1476

NO FUNCTIONAL CODE WAS CHANGED. ALL CHANGES ARE STRICTLY API DOCUMENTATION.

While cleaning gradle and considering moving to Java 21 for building (still will target Java 8, but also may target Java 17 and Java 21 in separate jars), new versions of Javadoc are more particular about javadoc warnings.

• One of the most common was

/**
 * @return the foo
 */
public String getFoo() { ... }

Which requires change to include a description other than the return

/**
 * Get the foo
 * @return the foo
 */
public String getFoo() { ... }

• Another common one was constants did not have javadoc comments. It seemed redundant when well named.

• Another was objects with only no-parameter constructors, so in reality had no constructor code. Javadoc didn't like this so no-parameter constructors were made and javadoc'ed

• There were some legitimate missing api, but almost entirely self documenting setters and getters.