[dotnet] [bidi] Implement Permissions extension module

[RenderMichael]

Implements the Permissions WebDriver BiDi module.

Reliant on #15420

Motivation and Context

Fixes #15329

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• I have read the contributing document.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[RenderMichael]

Aside from providing the Permissions module, this PR also provides a PermissionsBiDi which enables a "BiDi + permissions extension" built-in.

This fulfills the ask in the issue to do:

var permissions = await driver.AsBiDiPermissionsAsync(); 

However, anyone can extend the BiDi type and add the PermissionsModule + any other extensions they would like.

[nvborisenko]

It should not derive from BiDi.

[nvborisenko]

I guess this one we don't want conceptually.