Add legal and final strings (#1185)

* add legal and final strings

* removed unneeded suffixes from string ids

* removed unused strings and simplified string ids for vnext-only strings

* reword nostreams option

app/ui/downloadCompleted.js

@@ -12,7 +12,7 @@ module.exports = function(state) {
       </h1>
       <img src="${assets.get('completed.svg')}" class="my-12 h-48" />
       <p class="text-grey-darkest leading-normal">
-        ${state.translate('downloadFinishText')}
+        ${state.translate('trySendDescription')}
       </p>
       <p class="my-5">
         <a href="/" class="btn rounded-lg flex items-center mt-4" role="button"