feat: add loan button (undo-approval) (#860)

Fixes: #858

src/app/loans/loans-view/loan-account-actions/loan-account-actions.component.ts

@@ -1,6 +1,10 @@
-import { Component, OnInit } from '@angular/core';
+/** Angular Imports. */
+import { Component } from '@angular/core';
 import { ActivatedRoute, Router } from '@angular/router';
 
+/**
+ * Loan Account Actions component.
+ */
 @Component({
   selector: 'mifosx-loan-account-actions',
   templateUrl: './loan-account-actions.component.html',
@@ -9,11 +13,18 @@ import { ActivatedRoute, Router } from '@angular/router';
 export class LoanAccountActionsComponent {
 
   /** flag object to store possible actions and render appropriate UI to the user */
-  actions: { close: boolean } = { close: false };
+  actions: { close: boolean, undo_approval: boolean } = { close: false, undo_approval: false };
 
+  /**
+   * @param router Router.
+   * @param route Activated Route.
+   */
   constructor(private router: Router,
     private route: ActivatedRoute) {
     this.route.params.subscribe(params => {
+      if (params['action'].indexOf('-') > 0) {
+        this.actions[params['action'].replace('-', '_')] = true;
+      }
       this.actions[params['action']] = true;
     });
   }