Get-AzEventHubNamespace should accept Pipeline-Input from Get-AzEventHub

[Paxilein]

Description of the new feature

Currently it doesn't and complains about missing mandatory parameter: Namespace

Proposed implementation details (optional)

Thanks for the feedback! We are routing this to the appropriate team for follow-up. cc @jfggdl.

Issue Details

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Description of the new feature

Currently it doesn't and complains about missing mandatory parameter: Namespace

Proposed implementation details (optional)

Author:	Paxilein
Assignees:	-
Labels:	Event Hubs, Service Attention, customer-reported, feature-request, question
Milestone:	-

[dingmeng-xue]

EventHub team, please help to evaluate this feature request.

[axisc]

@hakashya Can you make the recommended edits and make the PR so that this issue is addressed? Thanks