Move Operation helper types to Azure.Core

[annelo-msft]

We need to move the following files out of generator shared source in the autorest.csharp repo into Azure.Core shared source in the azure-sdk-for-net repo:

• IOperationSource
• LowLevelFuncOperation
• LowLevelOperationHelpers
• NextLinkOperationImplementation
• OperationFinalStateVia
• OperationInternals
• OperationInternalsOfT
• OperationOrResponseInternals
• OperationOrResponseInternalsOfT
• HttpPipelineExtensions

This is for two reasons:

• We need to be able to modify operation types without being blocked by generator merge to repo processes
• We need to consolidate all the operation types in a single place so we can begin refactoring and improving the LRO types as a unified story

[annelo-msft]

@AlexanderSher, @m-nash, do you have any concerns about this?

[ShivangiReja]

There is an issue to move HttpPipelineExtensions methods to Azure.Core. Can we do this as a part of this issue?

[AlexanderSher]

These types should be just removed:

OperationOrResponseInternals
OperationOrResponseInternalsOfT

Also, we need to fix generated code so that OperationInternals and OperationInternalsOfT are not used anywhere and get rid of them as well.

[annelo-msft]

@AlexanderSher, by removed, do you mean deleted from both repos?

[AlexanderSher]

We should also try to get rid of IOperationSource, but that is more complicated thing to do.

[annelo-msft]

Duplicate of Azure/azure-sdk-for-net#28369