Prepare validation data for wflow

[hboisgon]

For now we only prepare model input data but could be useful to export some validation data as well such as:

• Discharge or precipitation observation data (eg GRDC)
• Satellite data like GLEAM for evaporation-interception or snow cover from MODIS
• Reservoir and lake area (or volume) timeseries from Global Water Watch
• Others...

[laurenebouaziz]

• download to p-drive data and add to data_catalog
• add data of AXA project
• preprocess script of GRDC to netcdf or adapt data_adaptor to enable multiple csv files in one geodataset
• add a export_data function in the model API (core) so that we can call export_data directly from inifile. bbox of the model, tuple and list of filenames and output folder in model - validation (output folder and bbox are fixed arguments in the model API).
• create templates of wflow_hydromt ini file to generate additional wflow output through [setup_config_output_timeseries] so that we can save extra variables from the model to compare with external data. and add in the template the corresponding export_data.
• add template post process functions in hydromt_wflow (see sphinx functions which start with plot_) -- mod.results and read in evaluation data from the export_data folder and make plot_ functions (in wflow.py) of predefined plots, skill scores etc. (read in the export_data folder through the data_catalog of the model).

in wflow.py:
plot_dischage(
discharge_fn=grdc,
starttime = "2010-01-01",
endtime = "2011-01-01",
ids = [12223434, 12243545,]
)

read in data
read in self.results
enter a new workflow or same level as utils.py and wflow.py -- plot script with detailed functions.

and then this can be used in update function of wflow (through the ini file and directly in pyhton script).
[plot_dicharge]