PDO plugin: Reflections

* com.noccy.pdo: Implemented reflection for PDO databases,
  tables and columns. Reflectors for MySQL and Sqlite.
* com.noccy.pdo: Added pdo:inspect command.
* com.noccy.docker: Added basic stack management and commands.
* com.noccy.docker: Moved commands to dedicated namespace.
* Environment: readConfig and writeConfig helper added, with
  a flag to use the global config dir ~/.config/spark.

plugins/com.noccy.pdo/Reflection/Reflector/MysqlColumnReflection.php

@@ -0,0 +1,45 @@
+<?php
+
+namespace SparkPlug\Com\Noccy\Pdo\Reflection\Reflector;
+
+use PDO;
+use SparkPlug\Com\Noccy\Pdo\PdoResource;
+use SparkPlug\Com\Noccy\Pdo\Reflection\ColumnReflectionInterface;
+
+class MysqlColumnReflection implements ColumnReflectionInterface
+{
+
+    private array $meta;
+
+    public function __construct(PdoResource $db, array $meta)
+    {
+        $this->meta = $meta;
+    }
+
+    public function isPrimaryKey(): bool
+    {
+        return str_contains($this->meta['Key']??null, "PRI");
+    }
+
+    public function isNullable(): bool
+    {
+        return ($this->meta['Null']??null) == "YES";
+    }
+
+    public function getName(): string
+    {
+        return $this->meta['Field'];
+    }
+
+    public function getType(): string
+    {
+        return $this->meta['Type'];
+    }
+
+    public function getDefaultValue(): mixed
+    {
+        return $this->meta['Default'] ?? null;
+    }
+
+}
+