Feat: Classic UI option

[rhrlima]

Summary

Related to Issue #52

This PR adds an option to "Classic" UI themed windows.

It uses components and scripts that I put into an Unity Package called RO Flex UI, which is a collection of modular prefabs and scripts that should simplify the way we build UI in general, not only with the classic style.

What Changed?

• Add Player Info and Main Menu classic windows
• Add toggle to UI menu to swap between Modern and Classic styles
• Adds a UiManagerV2 as an initial idea to simplify the current UiManager script
• Adds a ClassicUI Scene with examples of windows created using the components
• Adds a custom Pixel Font based in the original RO.

PlayerInfo and MainMenu windows

I did only these two windows for now as simpler examples that do not require complex behavior.

PlayerInfo is the top-left window that displays Player's information like Name, Job, HP/SP, exp, etc.

MainMenu is the Escape window that usually shows options for character selection and keybindings, but here I added buttons for the same options we have at the bottom.

I had to rework a little bit of CharacterDetailBox and PlayerState and use an Observer pattern to update the old and new UI windows based on changes to the Player data. I believe this can be expanded and added to other parts of the code as well, to simplify how we handle controller and view scripts.

// Events emitted by PlayerState
public Action OnTextChanged;
public Action OnHpSPChanged;
public Action OnProgressChanged;
public Action OnWeightOrCurrencyChanged;
public Action OnStatsChanged;
public Action OnSkillsChanged;

// Example of UI script subscribing to PlayerState events
private void Subscribe()
{
    var state = PlayerState.Instance;
    if (state == null || subscribed)
        return;

    state.OnTextChanged += OnTextChanged;
    state.OnHpSPChanged += OnHpSpChanged;
    state.OnProgressChanged += OnProgressChanged;
    state.OnWeightOrCurrencyChanged += OnWeightAndZenyChanged;
    subscribed = true;
}

UiManagerV2

Follows the same basic idea from the current script with a dictionary of windows for management, and a list of openwindows, to control what to close.

It also proposes a self-register pattern, where the Window script can call during Start() something like:

UiManagerV2.Instance.RegisterWindow(WindowID.PLAYER_INFO, this, KeyCode.Q);

Which should simplify how we register windows, and possibly handle keyboard events.

Example

Working Player Info window

Examples of Classic Windows built using the components