This to make #29194 and the goal is to build a file system provider that connects to a FTP server. We want to support the following things

• stuff works with scheme, not authority
• show remote files in the explorer like normal files
• allow read, write, and delete files
• allow to list, create, delete folders

The outcome of this is a more mature and complete (internal and external) API and a sample that illustrates how to use it. And last but not least this is to identify debt and false-assumptions about running on a (local) file system.