AuTest: use exteneded help output to determin curl feature support (#7834)
AuTest: use exteneded help output to determin curl feature support (#7834)

I ran the AuTest suite with a recent development version of curl and
noticed that the proxy_protocol.test.py test was skipped because it
thought that the built curl version didn't have haproxy-protocol
support. It did have this support, but that version of curl didn't show
that option in the brief `--help` output but it was shown if `--help
all` was used. This change makes checking curl feature support use
`--help all` for all feature requests.
vmamidi/trafficserver,SolidWallOfCode/trafficserver,bryancall/trafficserver,duke8253/trafficserver,SolidWallOfCode/trafficserver,duke8253/trafficserver,bryancall/trafficserver,bryancall/trafficserver,vmamidi/trafficserver,pbchou/trafficserver,duke8253/trafficserver,vmamidi/trafficserver,pbchou/trafficserver,vmamidi/trafficserver,bryancall/trafficserver,duke8253/trafficserver,SolidWallOfCode/trafficserver,duke8253/trafficserver,duke8253/trafficserver,pbchou/trafficserver,SolidWallOfCode/trafficserver,SolidWallOfCode/trafficserver,vmamidi/trafficserver,pbchou/trafficserver,bryancall/trafficserver,SolidWallOfCode/trafficserver,bryancall/trafficserver,SolidWallOfCode/trafficserver,vmamidi/trafficserver,pbchou/trafficserver,duke8253/trafficserver,pbchou/trafficserver