Moved description into dl tag in message list component

[SriHV]

What is the context of this PR?

204

Moved description into dl tag in message list component.

To achieve this new param bodyLabel was added and ariaLabelMsg param was deprecated.

As per the deprecation implementation process available in confluence
(DEPRECATED) is added to the ariaLabelMsg param and NEW is added to the bodyLabel param in message list documentation.

How to review this PR

Inspect example-message-list.html in send and reply message patterns and check that the description is inside the dl tag.

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[rmccar]

As this is a deprecation we need to follow the process outlined in the "Deprecation Implementation and Release Process" in confluence we have set out. You have added the "(DEPRECATED)" tag but we need to follow the other parts of the process

[SriHV]

As this is a deprecation we need to follow the process outlined in the "Deprecation Implementation and Release Process" in confluence we have set out. You have added the "(DEPRECATED)" tag but we need to follow the other parts of the process

I had doubt on this one. I will add the rest now now