Add CBS dataset in `dataverbinders-datamart`

[dkapitan]

For easy access, add cbs dataset in project dataverbinders-datamart with following tables:

Catalog

• dataset_id
• dataset_description
• dataset_period_first_year: first year included in dataset
• dataset_period_last_year: last year included in dataset

Kerncijfers wijken and buurten

Combine data from 2013 onwards for easy historical comparison. Taking 2013 here, because earlier data has different format, so we'll leave integration of those for later.
https://www.cbs.nl/nl-nl/dossier/nederland-regionaal/wijk-en-buurtstatistieken

Nabijheidsstatistieken

Same as above, but then for nabijheidsstatistieken from 2006 onwards
https://www.cbs.nl/nl-nl/reeksen/nabijheidsstatistieken-per-wijk-buurt

Bevolkingsstatistieken per pc4

https://opendata.cbs.nl/statline/portal.html?_la=nl&_catalog=CBS&tableId=83502NED&_theme=266

Mapping pc6huisnummer tot buurten and wijken

Using this SQL query

select
  gwb.PC6 as postcode,
  gwb.huisnummer,
  gwb.Buurt2019 as buurt_code,
  brt.Buurtnaam_2019 as buurt_naam,
  gwb.Wijk2019 as wijk_code,
  wijk.Wijknaam_2019K_NAAM as wijk_naam,
  gwb.Gemeente2019 as gemeente_code,
  gem.Gemeentenaam2019 as gemeente_naam
from `dk-open-data.cbs.pc6hnr20190801_gwb` as gwb
left join `dk-open-data.cbs.buurt2019` as brt on brt.Buurtcode_2019 = gwb.Buurt2019 
left join `dk-open-data.cbs.wijk2019` as wijk on wijk.Wijkcode2019 = gwb.Wijk2019 
left join `dk-open-data.cbs.gem2019` as gem on gem.Gemcode2019 = gwb.Gemeente2019 

[galamit86]

Re Kerncijfers wijken and buurten (and Nabijheidsstatistieken) - if we want them to end up as a single table, then we need to combine them. How about adding a period column to indicate the relevant year? We can conform to CBS's period, I think they use something like 2016JJ00 to indicate numbers over all of 2016, for example, or just add a year column.