Implement a code that will clean up inline JavaScript from WordPress

[igorhrcek]

Is your feature request related to a problem? Please describe.
If we allow inline JS to exist then having strong CSP policies (#27) will have no real purpose.

Describe the solution you'd like
We should find an elegant, sustainable and flexible solution for hooking into any WordPress installation in order to add and execute certain code.

Describe alternatives you've considered
None

Additional context
We should use a MU plugins for this. Practically every time we need to change the behavior of the WordPress we could just copy the PHP file from our codebase to a MU plugin and then update the main plugin file to include the new files. That way we can easily add and remove certain security features and hook into WP.