[TOOLS][DOCKER] Rewrite the configuration script to use whiptail/dialog, and refactor

docker/db/docker-compose.fragment.sh

@@ -0,0 +1,31 @@
+#!/usr/bin/sh
+
+if [ "${DBMS}" = 'postgres' ]; then
+    cat <<EOF
+    db:
+        image: postgres:alpine
+        restart: always
+        tty: false
+        ports:
+            - 5432:5432
+        environment:
+            - PGDATA=/var/lib/postgres/data
+        env_file:
+            - ./docker/db/db.env
+        volumes:
+            - database:/var/lib/postgres/data
+
+EOF
+else
+    cat <<EOF
+    db:
+        image: mariadb
+        restart: always
+        tty: false
+        ports:
+            - 3306:3306
+        env_file:
+            - ./docker/db/db.env
+
+EOF
+fi