Worker Indexing - Making IFunctionMetadataProvider.GetFunctionMetadata() an async method

[surgupta-msft]

Epic - #7496

What problem would the feature you're requesting solve? Please describe.

To make IFunctionMetadataProvider.GetFunctionMetadata() an async method. This method is currently handled in a synchronous manner, but ideally, it should be an asynchronous operation.

[surgupta-msft]

Parent issue - #7496