Example Drogon configuration not matching the webviz schema

[asnyv]

Custom keys in the example testdata configuration do not match the schema generated by webviz schema, and increases risk of users defining custom keys that we later want to use ourselves:

webviz-subsurface-testdata/webviz_examples/webviz-full-demo.yml

Lines 18 to 84 in 6a4b3e9

	dm_ensembles: &dm_ensembles
	- sens_run
	# Ensembes used for history matching analysis
	hm_ensembles: &hm_ensembles
	- iter-0
	- iter-1
	- iter-2
	- iter-3
	# Shared settings
	obsfile: &obsfile ../01_drogon_ahm/share/observations/tables/ert_observations.yml
	scalfile: &scalfile ../01_drogon_ahm/realization-0/iter-0/rms/output/pyscal/pyscal_config_lowbasehigh.csv
	fipfile: &fipfile ../01_drogon_ahm/realization-0/iter-0/share/results/tables/fip.yml
	segyfiles: &segyfiles
	- ../01_drogon_ahm/realization-0/iter-0/share/results/seismic/seismic--amplitude_depth--20180701_20180101.segy
	- ../01_drogon_ahm/realization-0/iter-0/share/results/seismic/seismic--amplitude_depth--20200701_20190701.segy
	gridfile: &gridfile ../01_drogon_ahm/realization-0/iter-0/share/results/grids/geogrid.roff
	gridparameterfiles: &gridparameterfiles
	- ../01_drogon_ahm/realization-0/iter-0/share/results/grids/geogrid--phit.roff
	- ../01_drogon_ahm/realization-0/iter-0/share/results/grids/geogrid--facies.roff
	surfacefiles: &surfacefiles
	- ../01_drogon_ahm/realization-0/iter-0/share/results/maps/topvolon--ds_extract_geogrid.gri
	- ../01_drogon_ahm/realization-0/iter-0/share/results/maps/toptherys--ds_extract_geogrid.gri
	- ../01_drogon_ahm/realization-0/iter-0/share/results/maps/topvolantis--ds_extract_geogrid.gri
	- ../01_drogon_ahm/realization-0/iter-0/share/results/maps/basevolantis--ds_extract_geogrid.gri
	surfacenames: &surfacenames
	- Top Volon
	- Top Therys
	- Top Volantis
	- Base Volantis
	formationfile: &formationfile ../01_drogon_ahm/realization-0/iter-0/share/results/tables/formations_res_only.csv
	faultlinefile: &faultlinefile ../01_drogon_ahm/realization-0/iter-0/share/results/polygons/toptherys--gl_faultlines_extract_postprocess.csv
	wellfolder: &wellfolder ../01_drogon_ahm/realization-0/iter-0/share/results/wells
	meanmap_colors: &meanmap_colors
	- "#7f3b08"
	- "#b35806"
	- "#e08214"
	- "#fdb863"
	- "#fee0b6"
	- "#f7f7f7"
	- "#d8daeb"
	- "#b2abd2"
	- "#8073ac"
	- "#542788"
	- "#2d004b"
	rmsmap_colors: &rmsmap_colors
	- "#fff7ec"
	- "#fee8c8"
	- "#fdd49e"
	- "#fdbb84"
	- "#fc8d59"
	- "#ef6548"
	- "#d7301f"
	- "#b30000"
	- "#7f0000"

suggestion:
Include a new dict key like custom_settings, app_settings or etc where the users can define whatever they want, and which is included in the autogenerated webviz schema from webviz-config as a reserved key that we will not use for anything else later.

-> if included, we will need a PR in webviz-config