Added passthrough of escapeDeactivates to focus-trap

refs mainmatter#435
refs mainmatter#295

https://github.com/focus-trap/focus-trap is used internally for keeping focus inside a modal and for handling modal closing on certain events. If the consuming app wants to manage deactivation/close-inducing events itself then it needs some way to pass `focus-trap` config through to turn off that functionality.

- added `escapeDeactivates` to the options passed through from the `modals` service to the `focus-trap` initialisation

README.md

@@ -3,3 +3,4 @@ Not recommended for general use, this package will be removed if upstream become
 
 Custom changes:
 - added `allowOutsideClick` passthrough from the `modals` service to the `focus-trap` initialisation so `clickOutsideDeactivates` and `allowOutsideClick` and be used in tandem to allow wormholed content such as dropdowns to work inside of a modal
+- added `escapeDeactivates` passthrough from the `modals` service to the `focus-trap` initialisation so that deactivation/close event handling can be fully controlled by the consuming app

addon/components/modal.js

@@ -30,11 +30,12 @@ export default Component.extend({
   didInsertElement() {
     this._super(...arguments);
 
-    let { allowOutsideClick, clickOutsideDeactivates } = this.modals;
+    let { allowOutsideClick, clickOutsideDeactivates, escapeDeactivates } = this.modals;
     let element = document.getElementById(this.modalElementId);
     let options = {
       allowOutsideClick,
       clickOutsideDeactivates,
+      escapeDeactivates,
       fallbackFocus: `#${this.modalElementId}`,
       onDeactivate: () => {
         if (this.isDestroyed || this.isDestroying) {

addon/services/modals.js

@@ -11,8 +11,9 @@ export default Service.extend({
   }),
   top: alias('_stack.lastObject'),
 
-  allowOutsideClick: undefined,
+  allowOutsideClick: false,
   clickOutsideDeactivates: true,
+  escapeDeactivates: true,
 
   init() {
     this._super(...arguments);