Creating new grid breaks if axes labels not provided

Description of Bug

If I use assign_metrics_to_grid to make a new grid, and I don't provide a list of axes labels, it will crash and give a misleading error message:

  File "/home/wk9874/Documents/simvue/python-api/simvue/run.py", line 1434, in assign_metric_to_grid
    self._error(f"Grid '{grid_name}' is not defined.")
  File "/home/wk9874/Documents/simvue/python-api/simvue/run.py", line 606, in _error
    raise SimvueRunError(message)
simvue.exception.SimvueRunError: Grid 'test_metric_2d' is not defined.

I dont think axes labels should be required, it should probably default to 'x' for 2D metrics of ['x', 'y'] for 3D metrics. Although if you would prefer to be explicit and require axes labels, it should provide a more informative message

Steps To Reproduce

Code to reproduce the behavior:

import simvue
import numpy

with simvue.Run() as run:
    run.init("test")
    run.assign_metric_to_grid(metric_name="test_metric_2d", axes_ticks=numpy.arange(100))
    for i in range(10):
        run.log_metrics({"test_metric_2d": numpy.random.rand(10)}, time=i, step=i)

Expected behavior

Should create a grid and log a metric

Actual Behaviour

Error thrown

Screenshots

If applicable, add screenshots to help explain your problem.

Setup

• OS: Ubuntu 22.04
• Python version 3.10

Untersuche simvue/run.py rund um assign_metric_to_grid in Zeile 1434 und führe dann die Reproduktion mit numpy und fehlenden Achsenbeschriftungen aus. Bestätige, ob das beabsichtigte Verhalten darin besteht, das Grid mit Standardwerten zu erstellen oder einen klareren Validierungsfehler zu melden, und überprüfe, ob das resultierende Verhalten dem erwarteten Grid- und Metrikprotokollierungsablauf entspricht.