Assure that deleted cat/keys are working as expected

- A deleted cache-key would delete a merged cache-key as well
- Deleting a key in the Model results in reloading the config to assure any value from underlying files

src/Core/Config/Model/Config.php

@@ -71,6 +71,8 @@ class Config implements IManageConfigValues
 	{
 		try {
 			$this->configFileManager->saveData($this->configCache);
+			// reload after the save to possible reload default values of lower source-priorities again
+			$this->reload();
 		} catch (ConfigFileException $e) {
 			throw new ConfigPersistenceException('Cannot save config', $e);
 		}
@@ -116,7 +118,7 @@ class Config implements IManageConfigValues
 	/** {@inheritDoc} */
 	public function delete(string $cat, string $key): bool
 	{
-		if ($this->configCache->delete($cat, $key, Cache::SOURCE_DATA)) {
+		if ($this->configCache->delete($cat, $key)) {
 			$this->save();
 			return true;
 		} else {

src/Core/Config/ValueObject/Cache.php

@@ -55,6 +55,11 @@ class Cache
 	 */
 	private $source = [];
 
+	/**
+	 * @var array
+	 */
+	private $delConfig = [];
+
 	/**
 	 * @var bool
 	 */
@@ -232,6 +237,7 @@ class Cache
 		if (isset($this->config[$cat][$key])) {
 			unset($this->config[$cat][$key]);
 			unset($this->source[$cat][$key]);
+			$this->delConfig[$cat][$key] = true;
 			if (count($this->config[$cat]) == 0) {
 				unset($this->config[$cat]);
 				unset($this->source[$cat]);
@@ -313,6 +319,19 @@ class Cache
 			}
 		}
 
+		$delCategories = array_keys($cache->delConfig);
+
+		foreach ($delCategories as $category) {
+			if (is_array($cache->delConfig[$category])) {
+				$keys = array_keys($cache->delConfig[$category]);
+
+				foreach ($keys as $key) {
+					unset($newConfig[$category][$key]);
+					unset($newSource[$category][$key]);
+				}
+			}
+		}
+
 		$newCache = new Cache();
 		$newCache->config = $newConfig;
 		$newCache->source = $newSource;