HPCC-8191: WsEcl support for building REST URLs (HTTP-GET)

Add a link to the Links tag to get an example (unpopulated) REST URL.

Also add support to the generated form to make calls using HTTP-GET
which can be used to build specific REST URLs with the provided
parameters filled in.

Signed-off-by: Anthony Fishbeck <Anthony.Fishbeck@lexisnexis.com>