build: update to angular-v9.1.12 (#1215)

Fixes: #1216

src/app/accounting/accounting-rules/accounting-rules.component.ts

@@ -1,6 +1,8 @@
 /** Angular Imports */
 import { Component, OnInit, ViewChild } from '@angular/core';
-import { MatPaginator, MatSort, MatTableDataSource } from '@angular/material';
+import { MatPaginator } from '@angular/material/paginator';
+import { MatSort } from '@angular/material/sort';
+import { MatTableDataSource } from '@angular/material/table';
 import { ActivatedRoute } from '@angular/router';
 
 /**
@@ -21,9 +23,9 @@ export class AccountingRulesComponent implements OnInit {
   dataSource: MatTableDataSource<any>;
 
   /** Paginator for accounting rules table. */
-  @ViewChild(MatPaginator) paginator: MatPaginator;
+  @ViewChild(MatPaginator, { static: true }) paginator: MatPaginator;
   /** Sorter for accounting rules table. */
-  @ViewChild(MatSort) sort: MatSort;
+  @ViewChild(MatSort, { static: true }) sort: MatSort;
 
   /**
    * Retrieves the accounting rules data from `resolve`.

src/app/accounting/accounting-rules/view-rule/view-rule.component.ts

@@ -1,7 +1,7 @@
 /** Angular Imports */
 import { Component, OnInit } from '@angular/core';
 import { ActivatedRoute, Router } from '@angular/router';
-import { MatDialog } from '@angular/material';
+import { MatDialog } from '@angular/material/dialog';
 
 /** Custom Services */
 import { AccountingService } from '../../accounting.service';