[spring] Delegate Incorrectly generated when useOptional True

[esemplare]

Fix #17768: Delegate Incorrectly generated when useOptional True

• Update moustache dataType value to >optionalDataType section to use Optional DataType when it is a BodyParam and not reactive.

Added tests to ensure the Api and it's Delegate methods both use optional.

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Java Spring	@cachescrubber (2022/02) @welshm (2022/02) @MelleD (2022/02) @atextor (2022/02) @manedev79 (2022/02) @javisst (2022/02) @borsch (2022/02) @banlevente (2022/02) @Zomzog (2022/09) @martin-mfg (2023/08)

[martin-mfg]

LGTM

Thanks for the PR!