test(language-service): Add method to override inline template (#36890)

This commit adds a method `overrideInlineTemplate` to the
`MockTypescriptHost`. This allows us to override an inline template
in a Component without changing the TypeScript parts. This methods works
in a similar way as `MockTypescriptHost.override()`, which is used for
overriding external template.

PR Close #36890

packages/language-service/test/project/app/main.ts

@@ -16,12 +16,8 @@ import * as ParsingCases from './parsing-cases';
   imports: [CommonModule, FormsModule],
   declarations: [
     AppComponent,
-    ParsingCases.CaseIncompleteOpen,
-    ParsingCases.CaseMissingClosing,
-    ParsingCases.CaseUnknown,
     ParsingCases.CounterDirective,
     ParsingCases.HintModel,
-    ParsingCases.NoValueAttribute,
     ParsingCases.NumberModel,
     ParsingCases.StringModel,
     ParsingCases.TemplateReference,