Add Session Management instances (including Depenency Injection)

- Prerequesite for mocking Sessions
- Reduce "App" class complexity

src/Core/Session/MemorySession.php

@@ -0,0 +1,84 @@
+<?php
+
+namespace Friendica\Core\Session;
+
+/**
+ * Native Session functions for internal Session usage.
+ *
+ * Usable for backend processes (daemon/worker) and testing
+ */
+final class MemorySession implements ISession
+{
+	private $data = [];
+
+	public function start()
+	{
+		$this->clear();
+		return $this;
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function exists(string $name)
+	{
+		return isset($this->data[$name]);
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function get(string $name, $defaults = null)
+	{
+		return $this->data[$name] ?? $defaults;
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function set(string $name, $value)
+	{
+		$this->data[$name] = $value;
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function setMultiple(array $values)
+	{
+		foreach ($values as $key => $value) {
+			$this->data[$key] = $value;
+		}
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function remove(string $name)
+	{
+		if ($this->exists($name)) {
+			unset($this->data[$name]);
+			return true;
+		}
+
+		return false;
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function clear()
+	{
+		$this->data = [];
+		return true;
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function delete()
+	{
+		$this->data = [];
+		return true;
+	}
+}