Added configurable limit on custom themes

issue https://github.com/TryGhost/Team/issues/590

ghost/admin/app/components/modal-upgrade-host-limit-custom-theme.hbs

@@ -0,0 +1,21 @@
+
+<header class="modal-header" data-test-modal="delete-user">
+    <h1>Upgrade to enable custom themes</h1>
+</header>
+<button class="close" title="Close" {{on "click" this.closeModal}}>{{svg-jar "close"}}<span class="hidden">Close</span></button>
+
+<div class="modal-body">
+    <p>
+        Your current plan only supports official themes. You can install them from the <a href="https://ghost.org/marketplace/">Ghost theme marketplace</a>.
+    </p>
+</div>
+
+<div class="modal-footer">
+    <button {{on "click" this.closeModal}} class="gh-btn" data-test-button="cancel-upgrade">
+        <span>Cancel</span>
+    </button>
+
+    <button {{on "click" (action "upgrade")}} class="gh-btn gh-btn-black" data-test-button="upgrade-plan">
+        <span>Upgrade</span>
+    </button>
+</div>

ghost/admin/app/components/modal-upgrade-host-limit-custom-theme.js

@@ -0,0 +1,12 @@
+import ModalComponent from 'ghost-admin/components/modal-base';
+
+export default ModalComponent.extend({
+    actions: {
+        upgrade: function () {
+            const upgradeLink = this.model.upgradeLink;
+            window.open(upgradeLink);
+            this.closeModal();
+            return true;
+        }
+    }
+});

ghost/admin/app/controllers/settings/theme/uploadtheme.js

@@ -0,0 +1,10 @@
+import Controller from '@ember/controller';
+import {inject as service} from '@ember/service';
+
+export default class UploadThemeController extends Controller {
+    @service config;
+
+    get isAllowed() {
+        return !this.config.get('hostSettings')?.limits?.customThemes;
+    }
+}

ghost/admin/app/templates/settings/theme/uploadtheme.hbs

@@ -1,4 +1,4 @@
-<GhFullscreenModal @modal="upload-theme"
+<GhFullscreenModal @modal={{if this.isAllowed "upload-theme" "upgrade-host-limit-custom-theme"}}
     @model={{hash
         themes=this.themes
         activate=(route-action 'activateTheme')