Allow open detection (#27)

# Objective

Currently, there appears to be no way to tell if the console is open.
This is an almost required feature for a console as without it you
cannot block inputs while using the console or control how the mouse
behaves when the console is open.

## Solution

- Exposed the ConsoleUiState struct (keeping the fields as only crate
public)
- Exposed a function that returns whether the console is currently open

## Imagined usage

(with the console only conditionally included in the project)
```rust
fn keyboard_update(
    ...,
    #[cfg(debug_assertions)]
    console: Res<ConsoleUiState>
) {
    #[cfg(debug_assertions)]
    if console.open() {
        return;
    }

    ...
}
```

I can also see this being useful for locking and unlocking the mouse
based on whether the console is visible.

## Other

There also appears to be a `text_focus` field however this appears to
not be updated while the console is
presented. In the future, it'd be nice to have an `text_focused()`
method so that an open console only blocks
input when the text field is selected.

---------

Co-authored-by: Robert-M-Lucas <[email protected]>

src/ui.rs

@@ -24,7 +24,7 @@ pub const COMMAND_MESSAGE_NAME: &str = "console_command";
 pub const COMMAND_RESULT_NAME: &str = "console_result";
 
 #[derive(Default, Resource)]
-pub(crate) struct ConsoleUiState {
+pub struct ConsoleUiState {
     /// Wherever the console is open or not.
     pub(crate) open: bool,
     /// Whether we have set focus this open or not.
@@ -36,6 +36,13 @@ pub(crate) struct ConsoleUiState {
     pub(crate) command: String,
 }
 
+impl ConsoleUiState {
+    /// Whether the console is currently open or not
+    pub fn open(&self) -> bool {
+        self.open
+    }
+}
+
 fn system_time_to_chrono_utc(t: SystemTime) -> chrono::DateTime<chrono::Utc> {
     let dur = t.duration_since(web_time::SystemTime::UNIX_EPOCH).unwrap();
     let (sec, nsec) = (dur.as_secs() as i64, dur.subsec_nanos());