Remove global mediator command initialization from the Web IDE

MR: feat: remove global mediator commands from Web IDE (!474 - merged)

Description

Since the OAuth feature flag has been removed, we can also remove the mediator commands initialization from the Web IDE. This prevents us from requiring the VSBuffer module from VSCode, which is not included in the compilation/build starting from version 1.94.0.

Acceptance criteria

• Remove this line to register the mediator commands in VSCode bootstrap step
• Remove createBufferWrapper and other references of mediator commands in test and VSCode bootstrap.
• Removing mediator commands means that we will be unable to read files when loading the Web IDE while unauthenticated, let's Remove None authentication option from Example App while we're at it.