Dynamic Modals (#417)

* Move backdrop and click handler to modal service since they should not be used in web

* Add support for opening modals using ViewContainerRef

angular/src/components/modal/modal-injector.ts

@@ -0,0 +1,15 @@
+import {
+    InjectFlags,
+    InjectionToken,
+    Injector,
+    Type
+} from '@angular/core';
+
+export class ModalInjector implements Injector {
+    constructor(private _parentInjector: Injector, private _additionalTokens: WeakMap<any, any>) {}
+
+    get<T>(token: Type<T> | InjectionToken<T>, notFoundValue?: T, flags?: InjectFlags): T;
+    get(token: any, notFoundValue?: any, flags?: any) {
+        return this._additionalTokens.get(token) ?? this._parentInjector.get<any>(token, notFoundValue);
+    }
+}