Vismach: Merge functions from twp-vismach.py

[Sigma1912]

This merges the added functionality in 'twp_vismach.py' to the standard 'vismach.py'
Thus the two vismach models that used 'twp_vismach' can now use the standard 'vismach.py' and 'twp_vismach.py' can be removed.

The indenting in the existing vismach code is messy. I have kept most of it to make the changes more easy to follow.

Note that on some systems there is an error message that is related to the text overlay ('hud') object. This is preexisting, prints once and only if a text overlay has been added to the scene:

Exception in Tkinter callback
Traceback (most recent call last):
  File "/usr/lib/python3.11/tkinter/__init__.py", line 1948, in __call__
    return self.func(*args)
           ^^^^^^^^^^^^^^^^
  File "/home/user/git/linuxcnc-master/lib/python/rs274/OpenGLTk.py", line 374, in tkExpose
    self.tkRedraw()
  File "/home/user/git/linuxcnc-master/lib/python/rs274/OpenGLTk.py", line 351, in tkRedraw
    self.redraw()
  File "/home/user/git/linuxcnc-master/lib/python/vismach.py", line 869, in redraw
    self.hud.draw()
  File "/home/user/git/linuxcnc-master/lib/python/vismach.py", line 718, in draw
    glOrtho(0.0, self.app.winfo_width(), 0.0, ypos, -1.0, 1.0)
  File "/usr/lib/python3/dist-packages/OpenGL/platform/baseplatform.py", line 415, in __call__
    return self( *args, **named )
           ^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/OpenGL/error.py", line 230, in glCheckError
    raise self._errorClass(
OpenGL.error.GLError: GLError(
	err = 1285,
	description = b'out of memory',
	baseOperation = glOrtho,
	cArguments = (0.0, 400, 0.0, 400.0, -1.0, 1.0)
)

The only in-tree vismach application that uses the current Hud feature seems to be /src/emc/usr_intf/axis/scripts/tracking-test.py. The functionality of this is unchanged other than the color of the hud display:

Current:

New:

[c-morley]

Is this something re should add to qt vismach too?

[Sigma1912]

Not sure. Maybe we should find a way for qtvismach to use the functions in vismach.py.

[Sigma1912]

@grandixximo
Thanks so much for spending the time to review this!