Remove @requiredargsconstructor which generates @ConstructorProperties on the all-args constructor, conflicting with the no-arg @JsonCreator. Change @JsonCreator to accept nullable parameters with defaults, matching the pattern from #1007.

This resolves the InvalidDefinitionException: Conflicting property-based creators reported in issue #1003.

Reorder recipes so IfElseIfConstructToSwitch runs before the switch expression conversion recipes. This ensures that if-else-if instanceof chains are converted to switches, then immediately to switch expressions in a single pass, instead of requiring two runs (fixes #1011).

* Fix IfElseIfConstructToSwitch null safety regression (issue #1013)

When converting instanceof chains to switch without an explicit null check,
emit `case null, default` instead of just `default` to preserve instanceof's
null-safe behavior. Previously, the recipe would generate code that throws NPE
when the switched variable is null, unlike the original if-else chain.

* Fix UpgradeToJava21Test expectation for case null, default

… and bring in line with Jetty EE9 list (#1017)