Visual Studio Code IntelliSense does not work for optional parameters in .bicepparam files.

[DanijelMalik]

Bicep version
0.28.1 (but it's probably an issue in the previous versions too)

Describe the bug
Visual Studio Code IntelliSense does not work for optional parameters in .bicepparam files....however it works for modules.

// Mod.bicep
type Resource = {
  name: string
  resourceGroupName: string?
}

param storageAccount Resource?

resource StorageAccount 'Microsoft.Storage/storageAccounts@2023-05-01' existing = if (storageAccount != null) {
  name: storageAccount.?name ?? ''
  scope: resourceGroup(storageAccount.?resourceGroupName ?? '')
}

output storageAccountId string? = storageAccount == null ? null : StorageAccount.id

IntelliSense works when referencing a module from another .bicep file...

...but it doesn't work with .bicepparam files.