ServiceBus: Standard to Premium Namespace Migration API and $skip and $top parameters for list calls

[v-Ajnava]

Description

Servicebus: Standard to Premium Namespace Migration API -
1) Standard to Premium Namespace Migration API : added API to which supports Standard to Premium Migration
2) $skip and $top parameters (query) for the list calls to support fetch the required number of entities in list calls

Swagger Link:

1. Service Bus: added Standard to Premium namespace migration API azure-rest-api-specs#2854
2. Service Bus: added $skip and $top to list calls azure-rest-api-specs#2952

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[dsgouda]

LGTM