[IMP] merge auth_crypt into base

* store hashed passwords in the `password` column but gate it behind a
  computed field
* make the password field essentially write-only (SQL aside)
* add a "plaintext" hash type so it's possible to set the password in
  SQL directly & be able to login & have it automatically updated

Task 34211

odoo/addons/base/data/base_data.sql

@@ -16,7 +16,7 @@ CREATE TABLE res_users (
     id serial NOT NULL,
     active boolean default True,
     login varchar(64) NOT NULL UNIQUE,
-    password varchar(64) default null,
+    password varchar default null,
     -- No FK references below, will be added later by ORM
     -- (when the destination rows exist)
     company_id integer, -- references res_company,