Added new hud position options

[nathandoak]

I added new options for positioning the HUD. The main motivation is to be able to position the HUD away from sidebar ui extensions like ComfyUI-N-Sidebar and ComfyUI Workspace Manager - Comfyspace.

Image Chooser HUD: horizontal side

• options ["Left", "Right"]
• This option toggles the HUD's position based on either the left or right edge of the screen. Left is default.

Image Chooser HUD: horizontal position

• slider values are 0-500 inclusive in increments of 1
• This option sets the number of pixels of offset from the selected edge. 10 px is the default.

Image Chooser HUD: show/hide

• boolean checkbox
• This option breaks out hud visibility from the vertical position setting. true (visible) is the default.

Other changes include:

• updating the range of the vertical position to 0-500 inclusive
• minor whitespace changes
• renamed the original position setting to vertical position including existing functions
  • The original position setting name was not changed to maintain backward-compatibility

[chrisgoringe]

Thanks; nice changes (and always appreciate people thinking about backward compatibility!)