Prettied, Linted and updated angular.json according to the latest schematic of Angular CLI.

Now all that is needed is to make it ready for strict compiling.
Removed eslint-plugin-prettier as it is not recommended and causes errors for both eslint and prettier

Bumped to v8.0.0

overlord/src/app/balance-sheet/balance-sheet.ts

@@ -1,10 +1,5 @@
-export class BalanceSheetItem {
-  name?: string;
-  group?: string;
-  amount?: number;
-  subAmount?: number;
-  order: number;
-}
+import { BalanceSheetItem } from './balance-sheet-item';
+
 export class BalanceSheet {
   date: string;
   body: BalanceSheetItem[];