This is very simple function that you can add to your ISE profile that allows a file-open dialog box that looks specifically for ISO files and uses the Mount-DiskImage Command.
Function Mount-ISO {
$FileBrowser = New-Object System.Windows.Forms.OpenFileDialog -Property @{
InitialDirectory = [Environment]::GetFolderPath('Desktop')
Filter = 'ISO-Images (*.ISO)|*.iso'
}
$null = $FileBrowser.ShowDialog()
Mount-DiskImage -ImagePath $FileBrowser.FileName
}