Adding documentation for EventData properties

[conniey]

Description

Adds documentation as to what objects can be put in EventData.getProperties

Fixes #31095

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• The pull request does not introduce [breaking changes]
• CHANGELOG is updated for new features, bug fixes or other significant changes.
• I have read the contribution guidelines.

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[azure-sdk]

API change check

API changes are not detected in this pull request.

[bvahdat]

Thanks @conniey for this adjustment. I am wondering if the provided listing is complete, see:

https://github.com/apache/qpid-proton-j/tree/main/proton-j/src/main/java/org/apache/qpid/proton/codec

What about:

• Array
• ByteBuffer
• List
• Long
• Map
• Void
• Timestamp

Shouldn't we also add all the corresponding Java primitive types as well?

I also wonder if we should list all the supported Qpid Proton's own custom types:

https://github.com/apache/qpid-proton-j/tree/main/proton-j/src/main/java/org/apache/qpid/proton/amqp

Such as Binary, Symbol, UnsignedShort etc.