Apply needs_quotes list after filtering

[kadamwhite]

It is counterintuitive that the configuration value can

• omit quotes
• be a raw string

but that the values returned from altis.security.browser.filter_policy_value must have quotes and cannot be a raw string. I propose moving the logic within filter_policy_value around, to execute the array casting and quoting logic as the last step of the function, post-filtering, so that all filters can return directive values in the same (flexible) formats.