contrib/templates: reset padding for checkboxes in special forms

[hom3mad3]

This PR addresses an issue with padding for checkboxes using the predefined BerlinOnline classes. Instead of globally resetting the BO styles, I am introducing a utility class to selectively remove padding for the special forms that require it.

login and account pages forms

grey forms (panel--heavy)

Tasks

• [ ] PR name contains story or task reference
• [ ] Steps to recreate and test the changes
• [ ] Documentation (docs and inline)
• [ ] Tests (including n+1 and django_assert_num_queries where applicable)
• [x] Changelog

[vellip]

@hom3mad3 Can't we do (pseudo-code)...

.panel--heavy .form-check {
    padding: $some-padding;
}

or

:not(.panel--heavy) .form-check {
    padding: 0;
}

Or am I missing something?

[hom3mad3]

@vellip i'm probably so afraid of globally resetting stuff at this point 😂 but i prefer your solution 👍🏼

[hom3mad3]

@vellip thanks! removed the BS