color: add HSV slider mode alongside RGB/RGBA

nk_console_color_data (nuklear_console_color.h:4) only supports NK_RGB and NK_RGBA. Nuklear has nk_color_hsv_f() / nk_hsv_f() built in, so HSV is a natural addition for use cases like hue-based palette pickers.

Suggested Implementation

• Add NK_CONSOLE_COLOR_HSV (and optionally NK_CONSOLE_COLOR_HSVA) to the format enum.
• Store H/S/V as floats; convert to/from struct nk_color on read/write.
• Render three sliders labelled H / S / V instead of R / G / B.

QA

nk_console_color(parent, &col, NK_CONSOLE_COLOR_HSV) renders H/S/V sliders, and the bound nk_color reflects the correct RGB equivalent.

Start in nk_console_color.h at nk_console_color_data and the nk_console_color entry point, then review nk_color_hsv_f() and nk_hsv_f(). Add the HSV format and H/S/V slider behavior described in the issue, with conversion to the bound struct nk_color. Done means nk_console_color(parent, &col, NK_CONSOLE_COLOR_HSV) renders H/S/V sliders and updates the RGB color correctly.