Doesn't work with libs using style-loader

[ostrolucky]

style-loader is webpack loader which allows libraries to import css into their js library. The way it works is it dynamically creates <style> element first time js library is used. This is used by eg ckeditor 5.

Now, here's a problem. Ajaxcom removes <style> elements each time there is new page load and injects the ones it got via backend. This dynamic <style> is of course not in there, so won't be re-added. Additionally, style-loader doesn't check for presence of this <style> in following runs.

What happens from user POV is that everything is ok when such library is used for a first time, but when ajaxcom loads page again, this <style> is missing now and html added by this library is unstyled.

ref: ckeditor/ckeditor5#960