hp_procurve_show_interfaces_brief: support stacked port names

[julmanglano]

ISSUE TYPE

• Bugfix Pull Request

COMPONENT

hp_procurve, show interfaces brief

SUMMARY

The PORT capture group was anchored to [a-zA-Z0-9\-]+, which excludes
the / character used in stacked-switch port naming.

On a stacked HP/Aruba ProCurve switch, ports are named 1/1, 1/2,
…, 2/1, etc. None of those names match the existing regex, so the
showintbrief2 state hits its catch-all ^. -> Error rule and parsing
aborts on the very first interface.

This PR broadens the regex to [a-zA-Z0-9\-/]+, allowing the slash.
No other capture groups change, no schema change, and the five existing
fixtures (standalone-switch outputs) continue to pass.

The new show_interfaces_brief2.{raw,yml} fixture covers an 84-row
stacked output with a mix of 1/N, 2/N, and trunk-named ports.

[mjbear]

@julmanglano
Thank you for the PR!

I made a couple of minor changes.

• Reduced some of the duplication from the test data file
• Renamed the raw test data name be more descriptive (not a requirement, but several other files had names we purposefully set in past PRs so I adjusted this one)