student download all the things

closes CNVS-20007

test plan:
 - navigate to a student's profile settings page
 > there should be a button on the right side bar that says 'Download Submissions'
 - click that link
 > it should take you to /dashboard/data_exports
 > the page should say 'Download Submissions' with a friendly message underneath it
 > you should be able to click 'Create Export' and download all your submissions

Change-Id: Ifefeaffbabd1ddd211ead43f95c81b26b4001fef
Reviewed-on: https://gerrit.instructure.com/53233
Reviewed-by: Ryan Taylor <rtaylor@instructure.com>
Tested-by: Jenkins
QA-Review: Amber Taniuchi <amber@instructure.com>
Product-Review: Hilary Scharton <hilary@instructure.com>

app/views/content_exports/index.html.erb

@@ -1,15 +1,25 @@
-<% title = @context.is_a?(Course) ? t('content_exports', "Content Exports") : t('user_data_exports', "User Data Exports") %>
+<%
+  title = @context.is_a?(Course) ? t('content_exports', "Content Exports") : t('user_data_exports', "Download Submissions")
+  friendly_message = @context.is_a?(Course) ? nil : t("Creating a Submission Export will allow you to download a zip file of all your assignment submissions in all of your present and past courses. This could be a big file, so it may take a while. You can navigate away from the page and come back later.")
+%>
+
 
 <% add_crumb title %>
 <% content_for :page_title do %><%= title %><% end %>
 
 <div>
   <h1><%= title %></h1>
-  
+
+  <% if friendly_message %>
+    <p><%= friendly_message %></p>
+  <% end %>
+
   <div class="export_messages" style="<%= hidden %>">
     <div class="ui-state-error error_message"></div>
   </div>
-  
+
+  <hr />
+
   <div id="export_files">
     <% @exports.each do |export| %>
       <% unless export.running? %>
@@ -32,6 +42,8 @@
     <% end %>
   </div>
 
+  <hr />
+
   <div class="form" style="<%= hidden if @current_export_id %>">
     <% if @context.is_a?(Course) %>
       <%= form_tag course_content_exports_path(@context.id), :id => "exporter_form" do %>
@@ -67,7 +79,7 @@
       <% end %>
     <% end %>
   </div>
-  
+
   <div class="progress_bar_holder" style="<%= hidden unless @current_export_id %> margin-top: 10px;">
       <div class="export_progress"></div>
       <% if @context.is_a?(Course) %>

app/views/profile/profile.html.erb

@@ -15,6 +15,7 @@
     <% if mfa_settings == :optional && @user.otp_secret_key %>
       <a href="<%= disable_mfa_path('self') %>" class="btn button-sidebar-wide" id="disable_mfa_link"><%= image_tag "unlock.png" %> <%= t('links.disable_mfa', "Disable Multi-Factor Authentication") %></a>
     <% end %>
+    <a href="<%= dashboard_content_exports_path %>" class="btn button-sidebar-wide"><i class="icon-download"></i> <%= t("Download Submissions") %></a>
     <% if show_request_delete_account %>
        <a href="<%= request_delete_account_link %>" class="btn button-sidebar-wide"> <%= t('Delete My Account') %></a>
     <% end %>