refactor: PKcols in table, ViewKeyDependency type

* Get PKcols inside tables - done with SQL for tables and
  with an additional step in Haskell for views.

  This fixes an fk column being considered as a pk column on views
  and corrects the test added on
  https://github.com/PostgREST/postgrest/pull/1875/files/1d549768580310e18aac4ffa6dbd01c5b77934a7#r853674126

* classify view key dependencies in SQL

* remove Column from Relationship

* Merge cols/fcols in Relationship and
  ensure allM2ORels and allViewsKeyDependencies fk columns
  are ordered - done by attnum in SQL

* Cardinality now contains relColumns instead of Relationship -
  this simplifies getJoinConditions.

CHANGELOG.md

@@ -48,6 +48,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
  - #2147, Ignore `Content-Type` headers for `GET` requests when calling RPCs. Previously, `GET` without parameters, but with `Content-Type: text/plain` or `Content-Type: application/octet-stream` would fail with `404 Not Found`, even if a function without arguments was available.
  - #2155, Ignore `max-rows` on POST, PATCH, PUT and DELETE - @steve-chavez
  - #2239, Fix misleading disambiguation error where the content of the `relationship` key looks like valid syntax - @laurenceisla
+ - #2254, Fix inferring a foreign key column as a primary key column on views - @steve-chavez
 
 ### Changed