## What changes were proposed in this pull request?

Add stripXSS and stripXSSMap to Spark Core's UIUtils. Calling these functions at any point that getParameter is called against a HttpServletRequest.

## How was this patch tested?

Unit tests, IBM Security AppScan Standard no longer showing vulnerabilities, manual verification of WebUI pages.

Author: NICHOLAS T. MARION <nmarion@us.ibm.com>

Closes #17686 from n-marion/xss-fix.