Allow using a CloudTable directly

[SindreSB]

Hi, this is more of a draft to get feedback on whether this is a wanted change.

When using Azure Functions, the Azure Table binding will give you a Cloud Table directly. This can be used with the library simply by getting the underlying client and table name, but I think it would be useful and simpler if this library support working on a table directly.

I haven't fully tested these changes, but wanted to get feedback on whether this is a useful change, or if you see any issues or anything speaking against it?

[daniel-chambers]

Given the popularity of Azure Functions, I'm in support of this change. Thanks for putting it forward. So long as we implement this in a way that does not break backwards compatibility for existing users (and a quick glance at your changes indicates this is the case), I'm good with it.

[SindreSB]

I'm currently facing some issues with using the library with Azure Functions, but once I figure those out I'll pick up on this PR. :)