Fix warnings upon executing `kwk_process.py`

Warnings from hatyan (consider suppressing) >> https://github.com/Deltares/hatyan/issues/272:

C:\DATA\hatyan\hatyan\schureman.py:57: PerformanceWarning: DataFrame is highly fragmented.  This is usually the result of calling `frame.insert` many times, which has poor performance.  Consider joining all columns at once using pd.concat(axis=1) instead. To get a de-fragmented frame, use `newframe = frame.copy()`
  v0uf_base_forf = v0uf_base_forf.eval(shallow_eqs_pd_str.replace('-','+'), inplace=False) #for f only multiplication is applied, never division

Warnings form kwk_process.py:

c:\data\kenmerkendewaarden\examples\kwk_process.py:125: FutureWarning: The 'delim_whitespace' keyword in pd.read_csv is deprecated and will be removed in a future version. Use ``sep='\s+'`` instead
  yearmeanHW = pd.read_csv(file_yearmeanHW, delim_whitespace=True, skiprows=1, names=['datetime','values'], parse_dates=['datetime'], na_values=-999.9, index_col='datetime')/100
c:\data\kenmerkendewaarden\examples\kwk_process.py:126: FutureWarning: The 'delim_whitespace' keyword in pd.read_csv is deprecated and will be removed in a future version. Use ``sep='\s+'`` instead
  yearmeanLW = pd.read_csv(file_yearmeanLW, delim_whitespace=True, skiprows=1, names=['datetime','values'], parse_dates=['datetime'], na_values=-999.9, index_col='datetime')/100
c:\data\kenmerkendewaarden\examples\kwk_process.py:127: FutureWarning: The 'delim_whitespace' keyword in pd.read_csv is deprecated and will be removed in a future version. Use ``sep='\s+'`` instead
  yearmeanwl = pd.read_csv(file_yearmeanwl, delim_whitespace=True, skiprows=1, names=['datetime','values'], parse_dates=['datetime'], na_values=-999.9, index_col='datetime')/100
c:\data\kenmerkendewaarden\examples\kwk_process.py:234: FutureWarning: 'S' is deprecated and will be removed in a future version, please use 's' instead.
  times_pred_1mnth = pd.date_range(start=dt.datetime(tstop_dt.year,1,1,0,0)-dt.timedelta(hours=12), end=dt.datetime(tstop_dt.year,2,1,0,0), freq=f'{pred_freq_sec} S') #start 12 hours in advance, to assure also corrected
c:\data\kenmerkendewaarden\examples\kwk_process.py:329: FutureWarning: 'S' is deprecated and will be removed in a future version, please use 's' instead.
  prediction_av_corrBOI_one_roundtime = prediction_av_corrBOI_one.resample(f'{pred_freq_sec}S').nearest()
reshape_signal BOI SPRINGTIJ and write to csv: HOEKVHLD
c:\data\kenmerkendewaarden\examples\kwk_process.py:336: FutureWarning: 'S' is deprecated and will be removed in a future version, please use 's' instead.
  prediction_sp_corrBOI_one_roundtime = prediction_sp_corrBOI_one.resample(f'{pred_freq_sec}S').nearest()
reshape_signal BOI DOODTIJ and write to csv: HOEKVHLD
c:\data\kenmerkendewaarden\examples\kwk_process.py:343: FutureWarning: 'S' is deprecated and will be removed in a future version, please use 's' instead.
  prediction_np_corrBOI_one_roundtime = prediction_np_corrBOI_one.resample(f'{pred_freq_sec}S').nearest()

Warnings from kw.slotgemiddelden.py:

C:\DATA\kenmerkendewaarden\kenmerkendewaarden\slotgemiddelden.py:32: FutureWarning: 'AS' is deprecated and will be removed in a future version, please use 'YS' instead.
  allyears_DTI = pd.date_range(mean_array_todate.index.min(),mean_array_todate.index.max()+dt.timedelta(days=5*360),freq='AS')
C:\DATA\kenmerkendewaarden\kenmerkendewaarden\slotgemiddelden.py:32: FutureWarning: 'AS' is deprecated and will be removed in a future version, please use 'YS' instead.
  allyears_DTI = pd.date_range(mean_array_todate.index.min(),mean_array_todate.index.max()+dt.timedelta(days=5*360),freq='AS')
C:\DATA\kenmerkendewaarden\kenmerkendewaarden\slotgemiddelden.py:32: FutureWarning: 'AS' is deprecated and will be removed in a future version, please use 'YS' instead.
  allyears_DTI = pd.date_range(mean_array_todate.index.min(),mean_array_todate.index.max()+dt.timedelta(days=5*360),freq='AS')

Deltares-research / kenmerkendewaarden

Fix warnings upon executing `kwk_process.py` #42