🐛 fix content filters jumping when loading screen is shown

no issue
- ensure content filters in the loading screen have the same styles
- add session injection to `posts-loading` controller so that the authors dropdown doesn't appear when changing filters when logged in as an author

ghost/admin/app/controllers/posts-loading.js

@@ -1,10 +1,12 @@
 import Controller from 'ember-controller';
 import {readOnly} from 'ember-computed';
 import injectController from 'ember-controller/inject';
+import injectService from 'ember-service/inject';
 
 export default Controller.extend({
 
     postsController: injectController('posts'),
+    session: injectService(),
 
     availableTypes: readOnly('postsController.availableTypes'),
     selectedType: readOnly('postsController.selectedType'),

ghost/admin/app/templates/posts-loading.hbs

@@ -18,6 +18,7 @@
                 classNames="gh-contentfilter-menu gh-contentfilter-type"
                 triggerClass="gh-contentfilter-menu-trigger"
                 dropdownClass="gh-contentfilter-menu-dropdown"
+                matchTriggerWidth=false
                 data-test-type-select=true
                 as |type|
             }}
@@ -35,6 +36,7 @@
                 classNames="gh-contentfilter-menu gh-contentfilter-author"
                 triggerClass="gh-contentfilter-menu-trigger"
                 dropdownClass="gh-contentfilter-menu-dropdown"
+                matchTriggerWidth=false
                 data-test-author-select=true
                 as |author|
             }}
@@ -52,6 +54,8 @@
                 classNames="gh-contentfilter-menu gh-contentfilter-tag"
                 triggerClass="gh-contentfilter-menu-trigger"
                 dropdownClass="gh-contentfilter-menu-dropdown"
+                searchPlaceholder="Search tags"
+                matchTriggerWidth=false
                 data-test-tag-select=true
                 as |tag|
             }}
@@ -69,6 +73,8 @@
                 classNames="gh-contentfilter-menu gh-contentfilter-sort"
                 triggerClass="gh-contentfilter-menu-trigger"
                 dropdownClass="gh-contentfilter-menu-dropdown"
+                horizontalPosition="right"
+                matchTriggerWidth=false
                 data-test-order-select=true
                 as |order|
             }}