add pagination support

[DeepakRajendranMsft]

Description

Changes contain:

1. add pagination support for GET (list) commands
2. minor bug fix in GET NIC (format.xml)
3. removing redundant code

---

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[markcowl]

Wouldn't it be simpler to create a generic enumerator over IPage that returned an IEnumerable? You can find a sample of this code here: 9just needs to be made generic):

https://github.com/Azure/azure-powershell/blob/preview/src/ResourceManager/Common/Commands.ResourceManager.Common/Generated/Models/PageEnumerator.cs

https://github.com/Azure/azure-powershell/blob/preview/src/ResourceManager/Common/Commands.ResourceManager.Common/Generated/Models/PageEnumerablecs

[DeepakRajendranMsft]

@markcowl please take a look at the changes. i have removed the redundant code.

[EvgenyAgafonchikov]

LGTM

[DeepakRajendranMsft]

@markcowl could you please take another look

[markcowl]

Waiting on common code implementation for SupportsPaging

[cormacpayne]

@DeepakRajendranMsft LGTM

Does this PR contain all of the cmdlets that would need to use this new mechanism? Also, any additional test coverage needed for these changes?

[cormacpayne]

On-demand: http://azuresdkci.cloudapp.net/job/powershell-demand/1703/

[DeepakRajendranMsft]

@cormacpayne, As mentioned above, the problem was that to test it, we would require to create a lot of resources. and yes we have all the cmdlets that would use this. i tested this manually against our test clusters

Mark is OOF, approved offline with Scott