remove unused style sheets, add OnPush change detection

src/app/features/shared/containers/error/error.component.ts

@@ -1,8 +1,8 @@
-import { Component } from "@angular/core";
+import { ChangeDetectionStrategy, Component } from "@angular/core";
 
 @Component({
   selector: "app-error",
   templateUrl: "./error.component.html",
-  styleUrls: ["./error.component.sass"],
+  changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class ErrorComponent {}

src/app/features/shared/containers/loader/loader.component.ts

@@ -1,8 +1,8 @@
-import { Component } from "@angular/core";
+import { ChangeDetectionStrategy, Component } from "@angular/core";
 
 @Component({
   selector: "app-loader",
   templateUrl: "./loader.component.html",
-  styleUrls: ["./loader.component.sass"],
+  changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class LoaderComponent {}