Add support for configurable terminal modes (Fullscreen and Inline)

[phil-scott-78]

You can test it out in Program.cs by passing a new TerminalMode

var terminalMode = new InlineMode(5);
using var terminal = Terminal.Create(terminalMode);

To adjust the size while running tweak this to look for some keys for input

if (Console.KeyAvailable)
{
    var key = Console.ReadKey(true);
    switch (key.Key)
    {
        case ConsoleKey.Q:
            // Time to quit?
            running = false;
            break;
        case ConsoleKey.W:
            terminalMode.SetHeight(Math.Min(terminalMode.Height + 1, 40));
            break;
        case ConsoleKey.S:
            terminalMode.SetHeight(Math.Max(3, terminalMode.Height - 1));
            break;
        }
}

Theoretically Height could have a getter, but I worry I'm being naive about what else might need to happen on that change so felt a method felt more appropriate for setting it for whenever whatever I overlooked comes to head.