Account Issue Model and Resolution Flow + Troubleshooting guides (#1090)

* Rough draft of issue system

* Simplify design

* Remove stale files from merge conflicts

* STI for issues

* Cleanup

* Improve Synth api key flow

* Stub api key for test

test/controllers/issues_controller_test.rb

@@ -0,0 +1,17 @@
+require "test_helper"
+
+class IssuesControllerTest < ActionDispatch::IntegrationTest
+  setup do
+    sign_in users(:family_admin)
+  end
+
+  test "should get show polymorphically" do
+    issues.each do |issue|
+      get issue_url(issue)
+      assert_response :success
+      assert_dom "h2", text: issue.title
+      assert_dom "h3", text: "Issue Description"
+      assert_dom "h3", text: "How to fix this issue"
+    end
+  end
+end