Fix starting PostgreSQL in AppVeyor CI builds

Don't use "services" section as it's not flexible enough to allow
starting different versions of Postgres depending on the matrix entry
and just launch the service manually.

appveyor.yml

@@ -12,27 +12,31 @@ environment:
       BOOST_ROOT: C:\Libraries\boost_1_77_0
       MSSQL_VER: 2019
       POSTGRESQL_ROOT: C:\Program Files\PostgreSQL\13
+      POSTGRESQL_VER: 13
       MYSQL_VER: 80
       MYSQL_DIR: C:\Program Files\MySql\MySQL Server 8.0
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2022
     - G: "Visual Studio 16 2019"
       BOOST_ROOT: C:\Libraries\boost_1_73_0
       MSSQL_VER: 2017
       POSTGRESQL_ROOT: C:\Program Files\PostgreSQL\12
+      POSTGRESQL_VER: 12
       MYSQL_VER: 80
       MYSQL_DIR: C:\Program Files\MySql\MySQL Server 8.0
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
     - G: "Visual Studio 15 2017 Win64"
       BOOST_ROOT: C:\Libraries\boost_1_69_0
       MSSQL_VER: 2016
       POSTGRESQL_ROOT: C:\Program Files\PostgreSQL\11
+      POSTGRESQL_VER: 11
       MYSQL_VER: 57
       MYSQL_DIR: C:\Program Files\MySql\MySQL Server 5.7
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
     - G: "Visual Studio 14 2015 Win64"
       BOOST_ROOT: C:\Libraries\boost_1_60_0
       MSSQL_VER: 2014
       POSTGRESQL_ROOT: C:\Program Files\PostgreSQL\10
+      POSTGRESQL_VER: 10
       MYSQL_VER: 57
       MYSQL_DIR: C:\Program Files\MySql\MySQL Server 5.7
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
@@ -41,17 +45,16 @@ environment:
       MSSQL_VER: 2014
       BOOST_ROOT: C:\Libraries\boost_1_60_0
       POSTGRESQL_ROOT: C:\Program Files\PostgreSQL\9.4
+      POSTGRESQL_VER: 94
       MYSQL_VER: 57
       MYSQL_DIR: C:\Program Files\MySql\MySQL Server 5.7
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
 
-services:
-  - postgresql
-
 install:
   # Start these ones here as we can't specify the service name dynamically above.
   - net start mssql$SQL%MSSQL_VER%
   - net start mysql%MYSQL_VER%
+  - net start postgressql-x64-%POSTGRESQL_VER%
   - ps: |
       Import-Module C:\projects\soci\scripts\windows\Get-ODBCList.ps1
       $drivers_list = Get-ODBCList