Add two user-management-focused exceptions

exceptions/updates/MDInsufficientPassword.php

@@ -0,0 +1,27 @@
+<?PHP
+/**
+ * This file contains an exception class to be thrown if users try to set
+ * insufficient / too weak passwords.
+ *
+ * @file
+ *
+ * @author Joshua Ramon Enslin <joshua@museum-digital.de>
+ */
+declare(strict_types = 1);
+
+/**
+ * This file contains an exception class to be thrown if users try to set
+ * insufficient / too weak passwords.
+ */
+final class MDInsufficientPassword extends MDgenericInvalidInputsException {
+    /**
+     * Error message.
+     *
+     * @return string
+     */
+    public function errorMessage() {
+        //error message
+        return 'Insufficient / weak password: ' . $this->getMessage();
+
+    }
+}

exceptions/updates/MDUserPasswordsDoNotMatch.php

@@ -0,0 +1,27 @@
+<?PHP
+/**
+ * This file contains an exception class to be raised if users' password and
+ * password verification don't match.
+ *
+ * @file
+ *
+ * @author Joshua Ramon Enslin <joshua@museum-digital.de>
+ */
+declare(strict_types = 1);
+
+/**
+ * Custom exception class to be raised if users' password and password
+ * verification don't match.
+ */
+final class MDUserPasswordsDoNotMatch extends MDgenericInvalidInputsException {
+    /**
+     * Error message.
+     *
+     * @return string
+     */
+    public function errorMessage() {
+        //error message
+        return 'Passwords don\'t match: ' . $this->getMessage();
+
+    }
+}