Support alternative extensions for `.dib` files, e.g. `.dnb`, `.idnb`, `.pnb`, `.pgnb`

[cr3wdayt5p]

Is your feature request related to a problem? Please describe. Azure DevOps treat .dib extension as binary (see https://github.com/dotnet/interactive/issues/1583) – and they don't intend to change that (see https://github.com/dotnet/interactive/issues/1583#issuecomment-1761511119).

Describe the solution you'd like By simply supporting alternative file extensions for .dib files then users of Azure DevOps can easily work around the "issue" with Azure DevOps. This could be as simple as supporting .dib2 – but https://github.com/dotnet/interactive/issues/1583 list other suggestions: .dnb, .idnb, .pnb, .pgnb

Describe alternatives you've considered None, the Azure DevOps team don't want to change their product (.dib is a reserved extension for "device independent bitmap").

[nicystalker]

How about .dinb? I did not find any technological history tied to this file extension.

[StevenQuickGS1]

Using is an existing file extension is a real pain, Azure Devops is not the only tool that expects .dib to be device independent bitmap as opposed dotnet interactive notebook.

Adding an alternative file extension seems like a no brainer to me.