build: Replace Codelyzer and TSLint with Angular ESLint

Migrate from the deprecated TSLint to Angluar ESLint. Also fix current
linting issues in the code, in particular:

- Use strict equals operators (=== and !==)
- Remove empty lifecycle methods (mostly ngOnInit)
- Output bindings including aliases should not be named as standard dom
  events (submit)
- Async pipe results should not be negated

src/app/system/external-services/external-services.component.ts

@@ -1,5 +1,5 @@
 /** Angular Imports */
-import { Component, OnInit } from '@angular/core';
+import { Component } from '@angular/core';
 
 /**
  * External Services component.
@@ -8,15 +8,12 @@ import { Component, OnInit } from '@angular/core';
   selector: 'mifosx-external-services',
   templateUrl: './external-services.component.html',
 })
-export class ExternalServicesComponent implements OnInit {
+export class ExternalServicesComponent {
   // Initialize an array of 4 boolean values, all set to false
   arrowBooleans: boolean[] = new Array(4).fill(false);
 
   constructor() { }
 
-  ngOnInit() {
-  }
-
   /**
    * Popover function
    * @param arrowNumber - The index of the boolean value to toggle.