DML with time-to-event data

### Describe the feature you want to propose or implement

Time-to-event data is common in social science fields. It would be helpful to apply double machine learning framework on time-to-event data. One approach is to apply the causal survival forest model implemented by `grf` package, but it would be better to use different learners like xgboost in DoubleML framework.

### Propose a possible solution or implementation

_No response_

### Did you consider alternatives to the proposed solution. If yes, please describe

One solution is causal survival forest implemented by `grf` package. Please check [Causal survival forest](https://grf-labs.github.io/grf/reference/causal_survival_forest.html) for reference.

### Comments, context or references

Please check [Causal survival forest](https://grf-labs.github.io/grf/reference/causal_survival_forest.html) for reference.