Currently `csp_meta_tag` generates `name` attribute only.
However, in libraries like `Material-UI` and `JSS`, expect that the meta tag
that contains the nonce with `property` attribute.

https://material-ui.com/css-in-js/advanced/#how-does-one-implement-csp
https://github.com/cssinjs/jss/blob/master/docs/csp.md

This patch allows `csp_meta_tag` to specify arbitrary options and
allows `nonce` to be passed to those libraries.