gg: add text rendering, keyboard event handling for JS and other fixes (#12932)

vlib/gg/text_rendering.js.v

@@ -0,0 +1,9 @@
+module gg
+
+import gx
+
+pub fn (mut ctx Context) draw_text(x int, y int, text_ string, cfg gx.TextCfg) {
+	ctx.context.fillStyle = cfg.color.to_css_string().str
+	ctx.context.font = cfg.to_css_string().str
+	ctx.context.fillText(text_.str, x, y)
+}