Add support for Solid293

🤓 Before submitting the issue

[X] I have visited the Troubleshooting section.
[X] I have searched among the existing issues.
[X] I am using a Python virtual environment.
[X] I am using the latest version of PyMAPDL and its dependencies (fully updated virtual environment). You can update them using pip install --upgrade --upgrade-strategy eager ansys-mapdl-core in your activated virtual environment.

🔍 Description of the bug

Plotting a mesh of Solid293 crashes the gRPC link.

🕵️ Steps To Reproduce

from ansys.mapdl.core import launch_mapdl
mapdl = launch_mapdl(port=50057)
mapdl.clear()

# parameters
# geometric
R1 = 0.1
R2 = 0.12

mapdl.prep7()

# 2-D 6-NODE THERMAL SOLID
mapdl.et(2, 293, 1)
# AXISYMMETRIC BEHAVIOR
mapdl.keyopt(2, 3, 1)

# CREATE THE GEOMETRY FOR THE HOLLOW SPHERE
mapdl.pcirc(R1, R2, 0, 10)
# set element size and mesh the area
mapdl.esize(0.15*(R2-R1))
mapdl.type(2)
mapdl.mat(2)
mapdl.amesh(1)

mapdl.eplot(cpos='xy')

💻 Which Operating System are you using?

Windows

🐍 Which Python version are you using?

3.10

💾 Which MAPDL version are you using?

2023 R2

📝 PyMAPDL Report

Show the Report!

```text # PASTE HERE THE OUTPUT OF `python -c "from ansys.mapdl import core as pymapdl; print(pymapdl.Report())"` here ```

📝 Installed packages

Show the installed packages!

```text # PASTE HERE THE OUTPUT OF `python -m pip freeze` here ```

📝 Logger output file

Show the logger output file.

```text # PASTE HERE THE CONTENT OF THE LOGGER OUTPUT FILE. ```

ansys / pymapdl

Add support for Solid293 #3093