Replace classloader isolation strategy with process isolation strategy

[simonhauck]

🚀 Description

Replace the class loader isolations strategy with the process isolation strategy to fix memory leaks in large projects

📄 Motivation and Context

Fix for this issue which is caused by this issue
With the current strategy large projects can not be formatted due to memory leaks.
Fixes #203

🧪 How Has This Been Tested?

Added two new integration tests to verify that the ktfmtCheck and ktfmtFormat tasks work up to 1000 files as expected.

📦 Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

✅ Checklist

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.