refactor(ui5-illustrated-message): migrate to TS

[hinzzx]

With this change:

• Migrated the Illustrated-message component to TypeScript.
• Added slightly different logic in the onBeforeRendering() method - for validating if a given illustration name is correct or not.
• • If inccorect illustration name is provided - a warning is now given in the console, which let the developer know that there may be either a typo or wrong illustration name, and as same as before the default one ( "BeforeSearch" ) is loaded and shown.
• Error messages for missing modules are a little bit more specific now aswell;

[ilhan007]

@SAP/ui5-webcomponents-topic-p FYI