Update plugins to support standalone components

- ThemedComponent wrappers should always import their base component. This ensures that it's always enough to only import the wrapper when we use it.
- This implies that all themeable components must be standalone

→ added rules to enforce this
→ updated usage rule to improve declaration/import handling

lint/test/fixture/src/app/test/test-themeable.component.ts

@@ -10,6 +10,7 @@ import { Component } from '@angular/core';
 @Component({
   selector: 'ds-base-test-themeable',
   template: '',
+  standalone: true,
 })
 export class TestThemeableComponent {
 }

lint/test/fixture/src/app/test/themed-test-themeable.component.ts

@@ -13,6 +13,8 @@ import { TestThemeableComponent } from './test-themeable.component';
 @Component({
   selector: 'ds-test-themeable',
   template: '',
+  standalone: true,
+  imports: [TestThemeableComponent],
 })
 export class ThemedTestThemeableComponent extends ThemedComponent<TestThemeableComponent> {
   protected getComponentName(): string {

lint/test/fixture/src/themes/test/app/test/other-themeable.component.ts

@@ -0,0 +1,16 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+import { Component } from '@angular/core';
+
+@Component({
+  selector: 'ds-themed-test-themeable',
+  template: '',
+})
+export class OtherThemeableComponent {
+
+}

lint/test/fixture/src/themes/test/test.module.ts

@@ -8,11 +8,13 @@
 // @ts-ignore
 import { NgModule } from '@angular/core';
 
+import { OtherThemeableComponent } from './app/test/other-themeable.component';
 import { TestThemeableComponent } from './app/test/test-themeable.component';
 
 @NgModule({
   declarations: [
     TestThemeableComponent,
+    OtherThemeableComponent,
   ],
 })
 export class TestModule {

lint/test/fixture/tsconfig.json

@@ -1,6 +1,7 @@
 {
   "extends": "../../../tsconfig.json",
   "include": [
+    "src/**/*.ts",
     "src/**/*.ts"
   ],
   "exclude": ["dist"]

lint/test/testing.ts

@@ -20,6 +20,7 @@ import {
 themeableComponents.initialize(FIXTURE);
 
 TypeScriptRuleTester.itOnly = fit;
+TypeScriptRuleTester.itSkip = xit;
 
 export const tsRuleTester = new TypeScriptRuleTester({
   parser: '@typescript-eslint/parser',