Remove all extra XSS filtering

[dafeder]

After upgrading environments to PHP7, we've noticed that search facet items are being double-escape on characters like ampersands (&). Removing two different XSS filters we had added in fixes this, and we have not been able to reproduce any issues of XSS scripting vulnerability. This can be reversed if security scans detect a problem.

To reproduce

• Build current release of DKAN on PHP 7.1
• Create a group with an ampersand in the name
• View the search page and open the group facet; the ampersand should render as "&" and the link won't work.

QA Steps

• Build on a server running PHP 7.1
• Create a group with an ampersand in the name
• View the search page and open the group facet; the ampersand should render correctly and the link should work.

This also removes any licenses from the licenses facet that aren't defined in DKAN, so that we don't have ugly URLs in the facet (which lead to broken links anyway).

[janette]

Facets look good, and no warnings in the security scan.