flexible -C option for raso retrieve

[swester]

for Payerne (--loc pay), the option "-C 34" retrieves a high-resolution radiosounding. for other locations, this option has to be removed, otherwise no radiosounding at all is produced.
dwh_retrieve.py should automatically add -C 34 for payerne and omit or use -C 1 for all others.

[swester]

link to line, currently commented out:
https://github.com/MeteoSwiss-APN/plot_profile/blob/master/src/plot_profile/utils/dwh_retrieve.py#L318

[swester]

@leuty of all the remaining issues, this might be the most relevant one at the moment. if you continue looking at FLS over the swiss plateau i suggest to uncomment the mentioned line to quick fix this and have a highly resolved vertical profile.

[leuty]

we would have to explicitly check for the stationname