Remove PluginMetadata::operator== and != for PluginMetadata

Unlike the other metadata classes, they were only comparing plugin names
not full object equality. Checking full object equality isn't very
useful, so instead the operators have been replaced by a new
NameMatches() method that takes a non-regex plugin name string.

include/loot/metadata/plugin_metadata.h

@@ -236,20 +236,18 @@ public:
   LOOT_API bool IsRegexPlugin() const;
 
   /**
-   * Check if two PluginMetadata objects are equal by comparing their name
-   * values.
-   * @returns True if the plugin names are case-insensitively equal, false
-   *          otherwise.
+   * Check if the given plugin name matches this plugin metadata object's
+   * name field.
+   *
+   * If the name field is a regular expression, the given plugin name will be
+   * matched against it, otherwise the strings will be compared
+   * case-insensitively. The given plugin name must be literal, i.e. not a
+   * regular expression.
+   * @returns True if the given plugin name matches this metadata's plugin 
+   *          name, false otherwise.
    */
-  LOOT_API bool operator==(const PluginMetadata& rhs) const;
+  LOOT_API bool NameMatches(const std::string& pluginName) const;
 
-  /**
-   * Check if two PluginMetadata objects are not equal by comparing their name
-   * values.
-   * @returns True if the plugin names are not case-insensitively equal, false
-   *          otherwise.
-   */
-  LOOT_API bool operator!=(const PluginMetadata& rhs) const;
 private:
   std::string name_;
   std::optional<std::string> group_;