Adds new X-Effective-URL header to the xdebug plugin (#7931)

By adding "X-Effective-URL" to the request header "X-Debug",
the header "X-Effective-URL" header will be inserted to the
request headers with the effective URL value.

Exposes the TSHttpTxnEffectiveUrlStringGet() result, which is
the URL after the remap.
7 files changed