Add perf tests for Blob storage scenarios.

[Mohit-Chakraborty]

Create stand-alone test apps for Azure.Storage.Blobs and Microsoft.Azure.Storage.Blob

[jaschrep-msft]

These elements are just fine on their own, but this places current and legacy perf tests side-by-side when there are no controls into the parallelism of individual methods. It probably won't make a difference for testing small files, but when testing files that the SDKs partition for upload/download, they choose very different parallelism values by default; current chooses 2 and legacy chooses a function of logical cores on the machine. Unless we truly just want to compare defaults, which we could "fix" by just bumping the default core count for the current SDK, I worry the results generated by this code will lead us to wrong conclusions when comparing the different storage SDKs.

[Mohit-Chakraborty]

this places current and legacy perf tests side-by-side when there are no controls into the parallelism of individual methods.

The 2 tests are supposed to be run independently with individual controls of the degree of parallelism, load size and other tweakable parameters.