add option to start the gRPC connections without secret keys and add …

[mariostieriansys]

1. Add the option, via environment variable, to start the gRPC server in EnSight without a secret key. While this option is not intended for customers, it is still useful for debugging and the only way for allowing live stream connections between EnSight and Fluent for 232 installations. So I have added it to the pull request anyway

2. Add the option to monitor new timesteps when using load_data

[codecov-commenter]

Codecov Report

Merging #290 (84b4602) into main (46af244) will decrease coverage by 0.02%.
The diff coverage is 83.33%.

@@            Coverage Diff             @@
##             main     #290      +/-   ##
==========================================
- Coverage   82.65%   82.64%   -0.02%     
==========================================
  Files          17       17              
  Lines        2387     2391       +4     
  Branches      412      413       +1     
==========================================
+ Hits         1973     1976       +3     
  Misses        275      275              
- Partials      139      140       +1     

Files Changed	Coverage Δ
src/ansys/pyensight/core/locallauncher.py	69.56% <50.00%> (-0.44%)	⬇️
src/ansys/pyensight/core/session.py	90.61% <100.00%> (+0.05%)	⬆️