Catch UnknownExtensionException in getViteSettingFromExtensionDefinition function

Problem/Motivation

I have a disabled theme that is having vite configuration in it's info yml. When getViteSettingFromExtensionDefinition function is trying to find extensions with vite configuration inside it does not catch the exception if the theme is not installed.

👉 This might occur especially if you are having a disabled starterkit theme

Steps to reproduce

Add following lines to an uninstalled theme:

vite:
  enabled: true
  enableInAllLibraries: true
  enableInAllComponents: true

Proposed resolution

Add try/catch wrapper to catch uninstalled theme exception.