[datalake] Migrate file system operations to pipeline architecture

[roeap]

In this PR we migrate the file system operations which were not using the pipeline architecture to ... the pipeline architecture. Generally the into_future and into_stream pattern is employed.

A few things to note:

• One more request property needed lifetimes removed. This time I used Cow<'static, str>, I don't feel that I can give a qualified statement on what is better, just a gut feeling ... Cow.
• I needed to make a small change to the authorization policy. Here a question came up. We already have the StorageCredentials enum in the storage crate, should they be used instead of the new StorageSharedKeyCredential (@thovoll)
• for the into_stream on ListFileSystems I moved the Box::pin() into the function call, so that the caller would not have to worry about that, but I am not sure if there are any implications I missed. Just running the code works :). (@rylev)
• Since we parse a URL in the DataLakeClient constriuctor, I made it fallible. THis is probably not desired, but my thinking was to accept this for now, and address this in a follow up PR when the constructirs are updated based on How do we set Pipelines options to a Client? #591

As a next step I'd like to move the file operations and with that enable tests using the mock framework. I already have these changes ready to go from the large PR.

Once that is done, I think the initialization for the client needs to be revised based on #591 - I'd be happy to give that a shot as well, since for me as a user of the crates this is a very important change :).

[rylev]

Looks good! I had a few nit picks that I think would be worth fixing before merging, but I'll still mark this PR as approved.

[cataggar]

I'll make a pass over the storage errors after core & identity ship, but if the goal here is to put all azure_core::Error errors into Self::CoreError, then it can be done with a generic similar to:

azure-sdk-for-rust/sdk/data_cosmos/src/errors.rs

Lines 60 to 64 in 3e92851

	impl<T: Into<azure_core::ParsingError>> From<T> for ParsingError {
	fn from(error: T) -> Self {
	Self::Core(error.into())
	}
	}

but with Into<azure_core::Error>.

[roeap]

I think this needed to be the variant, since other core variants are handled above in more specific manner. this then leads to duplicate implementations.

[roeap]

my bad - this is not even a variant. However i tried your approach and there is conflicting implementations then, and I did not want to change around the error too much in this PR.

[cataggar]

Sounds good.

[thovoll]

Sorry, @roeap just getting to your question about using StorageCredentials. The .Net and Java SDKs have overloads that take StorageSharedKeyCredential or AzureSasCredential or TokenCredential. Here in Rust we could have differently named new functions, one for each credential type. This is how StorageAccountClient does it already. Behind the public interface, we could use something like StorageCredentials, or a trait, or directly convert to a policy.