CDN psd1 fix

[kuangweizhang]

1. Remove AzureCdn.psd1
2. Rename AzureRm.Cdn.psd1 to AzureRM.Cdn.psd1
3. Update wxi file and test

[azurecla]

Hi @kuangweizhang, I'm your friendly neighborhood Azure Pull Request Bot (You can call me AZPRBOT). Thanks for your contribution!

It looks like you're working at Microsoft (kzhan). If you're full-time, we DON'T require a contribution license agreement.

If you are a vendor, DO please sign the electronic contribution license agreement. It will take 2 minutes and there's no faxing! https://cla.azure.com.

TTYL, AZPRBOT;