294|Feature: Purge cache

Description of feature

• Added Purge Cache operator to be able to purge the cache from startup.
• Stax configuration: Added Purge Cache operator.

How to test it

1. Go into Stax configuration
2. Click on the trash button next to the cache directory path.

Checklist

Please check if your MR fulfills the following requirements:

• Unit tests have been added, if possible
• Documentation has been updated
• Build was run locally and any changes were pushed
• Lint has passed locally without error
• CHANGELOG.md has been updated

FYI: @awesome_dev_too