Ensemble name unique validation not working as expected

[dafeda]

Describe the bug
A clear and concise description of what the bug is.

To reproduce
Steps to reproduce the behaviour:

1. pip install ert
2. ert gui poly.ert
3. Run Ensemble experiment
4. To run another experiment, a unique Experiment name and Ensemble name is required. Ensemble name does not have to be unique when creating a new experiment.

Expected behaviour
Only Experiment name needs to be unique.

Screenshots

[oyvindeide]

In principle I agree with you, but as long as the plotter only shows Ensemble name that is the property which is most important that is unique, related to: #7894 and #7892

[frode-aarstad]

Closing this issue. Discussing how to proceed here: #8021