FIX: use autocomplete="discourse" to disable Chrome address autofill

https://stackoverflow.com/a/47822599/17174

Chrome 63 and up start ignoring `autofill="off"`

Per: https://bugs.chromium.org/p/chromium/issues/detail?id=468153#c164

> The tricky part here is that somewhere along the journey of the web autocomplete=off become a default for many form fields, without any real thought being given as to whether or not that was good for users. This doesn't mean there aren't very valid cases where you don't want the browser autofilling data (e.g. on CRM systems), but by and large, we see those as the minority cases. And as a result, we started ignoring autocomplete=off for Chrome Autofill data

So to work around this decision we now explicitly say: autocomplete="discourse"
when we don't want Chrome to randomly fill in addressed (aka. always)

app/assets/javascripts/discourse/templates/components/composer-title.hbs

@@ -4,6 +4,6 @@
              maxLength=titleMaxLength
              placeholderKey=composer.titlePlaceholder
              disabled=composer.loading
-             autocomplete="off"}}
+             autocomplete="discourse"}}
 
 {{popup-input-tip validation=validation}}

app/assets/javascripts/discourse/templates/components/composer-user-selector.hbs

@@ -7,7 +7,7 @@
                   tabindex="1"
                   usernames=usernames
                   hasGroups=hasGroups
-                  autocomplete="off"}}
+                  autocomplete="discourse"}}
 {{else}}
   <div class='ac-wrap composer-user-selector-limited' {{action "toggleSelector"}}>
     <span>{{limitedUsernames}}</span>

app/assets/javascripts/discourse/templates/components/d-editor.hbs

@@ -39,7 +39,7 @@
     </div>
 
     {{conditional-loading-spinner condition=loading}}
-    {{textarea autocomplete="off" tabindex=tabindex value=value class="d-editor-input" placeholder=placeholderTranslated disabled=disabled}}
+    {{textarea autocomplete="discourse" tabindex=tabindex value=value class="d-editor-input" placeholder=placeholderTranslated disabled=disabled}}
     {{popup-input-tip validation=validation}}
     {{plugin-outlet name="after-d-editor" tagName="" args=outletArgs}}
   </div>

app/assets/javascripts/discourse/templates/emoji-picker.raw.hbs.erb

@@ -19,7 +19,7 @@
 <div class='main-column'>
   <div class='filter'>
     {{d-icon 'search'}}
-    <input type='text' name="filter" placeholder="{{i18n 'emoji_picker.filter_placeholder'}}" autocomplete="off"/>
+    <input type='text' name="filter" placeholder="{{i18n 'emoji_picker.filter_placeholder'}}" autocomplete="discourse"/>
     <button class='clear-filter'>
       {{d-icon 'times'}}
     </button>

app/assets/javascripts/discourse/templates/invites/show.hbs

@@ -24,7 +24,7 @@
         <form>
           <div class="input username-input">
             <label>{{i18n 'user.username.title'}}</label>
-            {{input value=accountUsername id="new-account-username" name="username" maxlength=maxUsernameLength autocomplete="off"}}
+            {{input value=accountUsername id="new-account-username" name="username" maxlength=maxUsernameLength autocomplete="discourse"}}
             &nbsp;{{input-tip validation=usernameValidation id="username-validation"}}
             <div class="instructions">{{i18n 'user.username.instructions'}}</div>
           </div>

app/assets/javascripts/discourse/templates/modal/change-owner.hbs

@@ -6,7 +6,7 @@
     {{user-selector single="true"
                     usernames=new_user
                     placeholderKey="topic.change_owner.placeholder"
-                    autocomplete="off"}}
+                    autocomplete="discourse"}}
   </form>
 {{/d-modal-body}}
 

app/assets/javascripts/discourse/templates/modal/create-account.hbs

@@ -28,7 +28,7 @@
             <tr class="input">
                   <td class="label"><label for='new-account-username'>{{i18n 'user.username.title'}}</label></td>
                   <td>
-                  {{input value=accountUsername id="new-account-username" name="username" maxlength=maxUsernameLength autocomplete="off"}}
+                  {{input value=accountUsername id="new-account-username" name="username" maxlength=maxUsernameLength autocomplete="discourse"}}
                   </td>
             </tr>
             <tr class="instructions">

app/assets/javascripts/discourse/templates/modal/invite.hbs

@@ -22,7 +22,7 @@
           hasGroups=hasGroups
           usernames=emailOrUsername
           placeholderKey=placeholderKey
-          autocomplete="off"}}
+          autocomplete="discourse"}}
     {{else}}
       {{text-field value=emailOrUsername placeholderKey="topic.invite_reply.email_placeholder"}}
     {{/if}}