Integrate public sample dataset 'U2345030' for hourly CemaNeige model examples

It is now possible to include the example dataset 'U2345030' to run the demonstration scripts and examples for the hourly models with CemaNeige (RunModel_CemaNeigeGR4H and RunModel_CemaNeigeGR5H).
The underlying data for this catchment are now publicly available.

Benefits:

• Example scripts can be executed and tested end-to-end
• Facilitate reproducibility and onboarding for new users
• Simplifie maintenance and automated testing for the models

Tasks to perform:

• Ensure that the time series is not too long, to prevent the RDA file from becoming too large
• Remove all uses of \dontrun{} in the documentation examples for these models, so that the examples run by default
• Document the ‘U2345030’ dataset in the documentation pages for both BasinInfo and BasinObs
• Add \alias{U2345030} in the BasinObs documentation page
• Check that the model parameters have correct values to ensure the simulation runs efficiently