feat(chart): Implement axis labels rendering for all chart types

[moksha-hub]

Implement axis labels rendering for all chart types in the makepad-chart library to provide proper visual context for data visualization.

Motivation

Currently, charts render data points but lack axis labels, making it difficult for users to:

• Understand the scale of values on the Y-axis
• Identify categories/data points on the X-axis
• Interpret the data being visualized

Axis labels are essential for any production-ready charting library.

Proposed Solution

Add comprehensive axis label rendering support with the following components:

ChartAxis Component

• ChartAxis struct with configurable orientation (Horizontal / Vertical)
• Position support (Bottom, Top, Left, Right)
• Customizable styling (colors, fonts, padding)
• Show/hide options for line, ticks, and labels

AxisRenderer

• Coordinated rendering of X and Y axes
• Automatic tick label positioning
• Support for different axis positions

DrawLabel Element

• Text label rendering element for charts
• AxisLabelRenderer for batch label rendering
• Configurable text styling

Label Formatting

• Automatic number formatting with K (thousands) and M (millions) suffixes
• Custom label formatter support via closures
• Configurable font size and colors

Implementation Details

// Example usage
let axis = ChartAxis::new()
    .with_orientation(AxisOrientation::Vertical)
    .with_position(AxisPosition::Left)
    .with_label_formatter(|v| format!("${:.0}", v));

// Render labels
axis.render_labels(cx, &ticks, chart_area, scale);




--- PR: #3