feat(illustration): use illustration name as default module export

[nnaydenow]

Solution

Provide illustration name string as default export. This will allow developers to directly set the imported illustration name string to the ui5-illustrated-message component (as shown below) improving the DEV experience:

• easier to determine (within the IDE) if imported illustrations are still used
• immediate feedback (within the IDE) when import is missing for an illustration that is actually used

Changes

For the main collection of illustrations default export is illustration name (BeforeSearch) and for others collections of illustrations default export is collection name / illustration name (tnt/Calculator)

Usage

import "@ui5/webcomponents-fiori/dist/IllustratedMessage.js";
import sessionExpired from "@ui5/webcomponents-fiori/dist/illustrations/tnt/SessionExpired.js";

export default function App() {
  return (
      <ui5-illustrated-message name={sessionExpired}></ui5-illustrated-message>
  );
}

Also loaders now works with following pattern set/colletion/illustration-name (fiori/V4/UnableToLoad) instead of the old pattern colletion/illustration-name (V4/UnableToLoad)

Fixes: #8070
Fixes: #6735

[nnaydenow]

Need to provide option to have default import as named import of illustrations imported by relative path. Follow up: #8077