Added azure blob block driver support

[TheAzack9]

Hello,

I know there already exists a pr with this change here (#124), but it is a year old and possibly a bit outdated. I have tried my best to try update it such that it supports azure blobs, but i might have missed something since i'm not too well versed in nodejs and not too familiar with the environment. :) I'm not sure if it is better that it is a separate driver package or included directly in flydrive. (I expect it could be pretty useful for others aswell)

I should've updated most of the docs and Readme's aswell.

See (#68) for additional info

[TheAzack9]

Any feedback or thoughts?

[rijkvanzanten]

@RomainLanz Any blockers on this?

[RomainLanz]

Hey! 👋

Wow, this has been lost in all my notification....
Going to review it through the week!

Thanks for your contribution!

[TheAzack9]

Any developments @RomainLanz ? I hate to nag, but the feature would really help ;)

[RomainLanz]

Yes!

I see that there's a lot of code change that are not related to adding Azure Storage, could you please remove them?

[TheAzack9]

Which parts are you talking about? Most of the extra code changes are to document the Azure Storage support and adding tests.
The other change was that i had to make getStream async in order to support it with Azure Storage.

I'm just not quite sure which changes you are refering to 😅

If you just want a plain PR with only the changes necessary to add Azure Storage support, then i can fix that aswell :)

I noticed a small change that was wrong on my side, i will at least fix that part quickly. It was never my intention to remove a contributor...

[TheAzack9]

@RomainLanz sorry for excessive mentions, but i need a response to continue 😅

[Xalag]

It would be good to have Azure Storage support in flydrive. So I'm also very interested in this functionality. Thanks for all the work you put in so far!

I think the change of getStream to an async function is the only one which is not related to Azure Storage support. This introduces a breaking change for the lib and should therefore not be done.
The getStream function could stay as non-async if a intermediate stream is used.
Could perhaps look like this within the AzureBlobWebServices.ts

import { PassThrough, Readable } from 'stream'

private async getStreamAsync(): Promise<Readable> {
    const stream = await this.$containerClient.getBlobClient(location).download();
    if(!stream.readableStreamBody) {
        throw handleError(new Error("Blobclient stream was not available"), location);
    }
    return stream.readableStreamBody;
}

public getStream(): NodeJS.ReadableStream {
    const intermediateStream = new PassThrough({ highWaterMark: 1 });
    try {
        getStreamAsync().then(stream => {
            stream.pipe(intermediateStream)
        }).catch(error => {
            intermediateStream.emit('error', error);
        })
    } catch (error) {
        intermediateStream.emit('error', error);
    }
    return intermediateStream
}

[RomainLanz]

Hey @TheAzack9! 👋

Sorry to have took soooooo long to review this PR 😞.

Could you please write a small guide to setup an Azure account and create a container? I would need this to try your code on my machine and setup the CI after.

Thanks again!