Extract minify from option function to prevent a bug with minify JS

[CrochetFeve0251]

Description

Fix a problem where minified JS where created and deleted right after creating 404 errors. To fix this the logic to delete minify JS has been moved to a Subcriber and removed from the rocket_after_save_options function.

Fixes #2973

Type of change

• [x] Bug fix (non-breaking change which fixes an issue)

Is the solution different from the one proposed during the grooming?

No, the solution was right

How Has This Been Tested?

• [x] Automated tests
• [x] Manually on local env

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes
• [x] Any dependent changes have been merged and published in downstream modules

[CrochetFeve0251]

@Tabrisrp I saw some scenarios scripts in the issue from @Mai-Saad in pseudo code. Does you think that Behat and Gerkhin could be useful to communicate that kind of behavior and transform them into real tests?