Fix JSON BSD codec round-trip for nested struct fields

[kevinherron]

AbstractBsdCodec.encodeField cast every nested-struct value to UaStructuredType before handing it to the nested codec, which failed for JsonObjectCodec since its nested-struct values are raw JsonObjects. Wrap non-UaStructuredType values in BsdStructWrapper before invoking the nested encode, and add a matching decode-side branch in JsonObjectCodec.opcUaToMemberTypeScalar that unwraps BsdStructWrapper returned from nested decodes.

Re-enable JsonBsdCodecTest and GenericBsdCodecTest, which were @Disabled and would otherwise have caught this regression. The round-trip helper in AbstractBsdCodecTest now wraps/unwraps BsdStructWrapper to match the current encode/decode contract.

fixes #1741

[Copilot]

Pull request overview

This PR fixes JSON-backed BSD codec round-trip failures when encoding/decoding nested structured fields by aligning the nested-field encode/decode paths with the BsdStructWrapper contract introduced by the earlier refactor. It also re-enables previously disabled tests that would have detected the regression.

Changes:

• Wrap non-UaStructuredType nested-struct field values in BsdStructWrapper before invoking nested codec encoding (AbstractBsdCodec.encodeField).
• Unwrap BsdStructWrapper<JsonElement> results from nested decodes when building parent JSON objects (JsonObjectCodec.opcUaToMemberTypeScalar).
• Re-enable and update JSON/generic BSD codec tests to match the wrapper-based encode/decode contract.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
opc-ua-sdk/dtd-core/src/main/java/org/eclipse/milo/opcua/sdk/core/dtd/AbstractBsdCodec.java	Fixes nested structured-field encoding by wrapping non-UaStructuredType values before delegating to nested codecs.
opc-ua-sdk/dtd-core/src/main/java/org/eclipse/milo/opcua/sdk/core/dtd/json/JsonObjectCodec.java	Unwraps nested decode results returned as BsdStructWrapper<JsonElement> so nested structs embed correctly in parent JSON.
opc-ua-sdk/dtd-core/src/test/java/org/eclipse/milo/opcua/sdk/core/dtd/AbstractBsdCodecTest.java	Updates round-trip helpers to wrap inputs and unwrap decoded outputs to reflect current codec contracts.
opc-ua-sdk/dtd-core/src/test/java/org/eclipse/milo/opcua/sdk/core/dtd/json/JsonBsdCodecTest.java	Re-enables JSON BSD codec tests, including nested-struct coverage.
opc-ua-sdk/dtd-core/src/test/java/org/eclipse/milo/opcua/sdk/core/dtd/GenericBsdCodecTest.java	Re-enables generic BSD codec tests.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.