Add Visualization tab to simulate.

Also:
- Increased label width in mjUI tight theme spacing.
- Added `mjITEM_EDITFLOAT` for editing float values.
- Move mjUI numpad key codes to header file.
PiperOrigin-RevId: 535839953
Change-Id: Ibdc0a9a20be514caa5b487211212ed6f5b8a6ba9

include/mujoco/mjui.h

@@ -55,6 +55,8 @@
 #define mjKEY_F10        299
 #define mjKEY_F11        300
 #define mjKEY_F12        301
+#define mjKEY_NUMPAD_0   320
+#define mjKEY_NUMPAD_9   329
 
 
 //---------------------------------- primitive types (mjt) -----------------------------------------
@@ -97,6 +99,7 @@ typedef enum mjtItem_ {           // UI item type
   mjITEM_SLIDERNUM,               // slider, mjtNum value
   mjITEM_EDITINT,                 // editable array, int values
   mjITEM_EDITNUM,                 // editable array, mjtNum values
+  mjITEM_EDITFLOAT,               // editable array, float values
   mjITEM_EDITTXT,                 // editable text
 
   mjNITEM                         // number of item types