QtGP Misleading error if no Qt/Tools/Ninja and no ninja in environment path

Steps to reproduce:

• Open a clean qtquickview_(kotlin or java) project
• Make sure the environment does not have a Ninja in PATH or the path is not correct
• Make sure Qt/Tools/Ninja does not exist or is renamed
• Run application, it should fail and give you the error below

Bolded the misleading part of error: * Exception is:
org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':app:QtBuildTask'.
Caused by: org.gradle.api.GradleException: No valid path to Ninja found. Checked locations:
    - Manually specified path in build.gradle QtBuild extension: C:\Qt\Tools\Ninja\ninja.exe
    - Environment PATH
    - Default Qt installation directory: C:\Qt\Tools\Ninja

There is no manually defined path in build.gradle. We should print a differend error message in this case.