Have permissions decorators check user signed in

Rather than force us to write the decorators in a specific order let’s
just have one decorator call the other. This should make fewer lines of
code, and fewer annoying test failures. It also means that the same way
of raising a `401` (through the `current_app` method) is used
everywhere.

app/main/views/find_users.py

@@ -1,5 +1,5 @@
 from flask import flash, redirect, render_template, request, url_for
-from flask_login import current_user, login_required
+from flask_login import current_user
 
 from app import user_api_client
 from app.event_handlers import create_archive_user_event
@@ -10,7 +10,6 @@ from app.utils import user_is_platform_admin
 
 
 @main.route("/find-users-by-email", methods=['GET', 'POST'])
-@login_required
 @user_is_platform_admin
 def find_users_by_email():
     form = SearchUsersByEmailForm()
@@ -28,7 +27,6 @@ def find_users_by_email():
 
 
 @main.route("/users/<user_id>", methods=['GET'])
-@login_required
 @user_is_platform_admin
 def user_information(user_id):
     return render_template(
@@ -38,7 +36,6 @@ def user_information(user_id):
 
 
 @main.route("/users/<uuid:user_id>/archive", methods=['GET', 'POST'])
-@login_required
 @user_is_platform_admin
 def archive_user(user_id):
     if request.method == 'POST':