Migration of microsoft/ALAppExtensions#23225

Now that we have made several clients Universal code ready.
One of the main problems turned out to be the replacement of the file record and the file object (File.Create, File.Exists).
Some of our customers now use Azure Blob Service from the System app. Others don't have a good internet and now use a local microservice with REST API, others use Azure File Shares.
The problem is that every integration is different. I think many other partners will have the same problem.
To simplify access I have adopted the email module and created new file accounts.
With just one codeunit, a developer can now connect to various file services without having to know how they actually work. The code unit "File System" delviers everything taht is needed.

An additional PR contains three connector apps:
microsoft/ALAppExtensions#23225

This Apps will conenct:

• Azure Blob Storage
• Azure File Share
• SharePoint Online

All three service can be access over one unified interface!

New provider in the future could be:

• a OneDrive Provider
• Third Party file services

An example that shows how simple it is to use the new modules can be found here:
https://github.com/IceOnly/BC_FileSystem_Example

But before I go round the whole thing, I'm interested in whether there is any interest in the module at all.

Here are some Screenshots:

I have decided in favour of some restrictions. Paths must not start with a /. The only supported path separator is /. If services that require a \ are to be connected, this must be translated by the connector app.

These restrictions should ensure that the file service can be exchanged without upgrading data.

Assigned Workitems:
Fixes #2418
Fixes AB#559148