feat(span-name): add http.path to span name

[XinweiLiu28]

Proposed Changes

To display trace as "Kong, http.method http.path" by adding http.path to the span name.

Reason

The span name is displayed as "http.method" in the main dashboard.
It is difficult to distinguish traces at first glance.
By adding http.path to the span name, the trace would be displayed as "Kong, http.method http.path"

[CLAassistant]

All committers have signed the CLA.

[bforbis]

This feature goes against recommendations for span names, as it makes span names have high cardinality and therefore hard to classify spans into groups when doing span searches.

Refer to the Open telemetry spec on http spans.

Instrumentation MUST NOT default to using URI path as span name

[kikito]

@XinweiLiu28 I agree with bforbis, we should not do it by default. Consider perhaps including a config option to make the user opt-in (and exposing themselves to high cardinality).

[XinweiLiu28]

Thanks for the advice.
I added an option called "span_display_path", and the default value is false.