Improved config options for OIDC (#9)

Added many new configuration options, including claim configuration and client_secret/confidential client support. Also enables user linking & creates person entries upon first sign in.

custom_components/auth_oidc/views/templates/finish.html

@@ -0,0 +1,31 @@
+{% extends "base.html" %}
+{% block title %}Logged in!{% endblock %}
+{% block head %}
+{{ super() }}
+{% endblock %}
+{% block content %}
+<div class="text-center">
+    <div class="my-6">
+        <h2 class="text-xl font-semibold mb-6 text-gray-800">I want to login to this browser</h2>
+        <form method="post">
+            <input type="hidden" name="code" value="{{ code }}">
+            <button type="submit"
+                class="w-full py-2 px-4 bg-blue-500 text-white font-semibold rounded-lg shadow-md hover:bg-blue-700 focus:outline-none focus:ring-2 focus:ring-blue-400 focus:ring-opacity-75">
+                Login to Home Assistant in this browser
+            </button>
+        </form>
+    </div>
+
+    <hr class="my-12">
+
+    <div class="my-6">
+        <h2 class="text-xl font-semibold mb-4 text-gray-800">I am on a mobile device</h2>
+        <p class="mb-4">Your one-time code is: <b class="text-blue-600 text-xl">{{ code }}</b></p>
+        <p class="mb-4 text-sm">You have 5 minutes to use this code on any device.<br />The code can only
+            be used once.</p>
+        <p class="mb-4 text-sm">Please type the code into your app manually. If you don't see a code input, select
+            'Login with
+            OpenID Connect (SSO)' first.</p>
+    </div>
+</div>
+{% endblock %}