[EXPORTER] Add option to disable Prometheus otel_scope_name and otel_scope_version attributes

[timwoj]

Fixes #2442 (plus one bonus fix)

Changes

• Adds a new populate_otel_scope option to the PrometheusExporterOptions object defaulting to enabled, including an environment variable to control it
• Uses the option to enable/disable the otel_scope_name and otel_scope_version attributes added to instruments in Prometheus output
• Adds a new environment variable for controlling the populate_target_info option of PrometheusExporterOptions

I opted to use (abuse) the side effect of the scope variable being null for the actual disabling of the attributes here, instead of passing the option down through the method chain to where it's used. If that's undesirable, I can switch to passing it.

For significant contributions please make sure you have completed the following items:

• CHANGELOG.md updated for non-trivial changes
• Unit tests have been added
• Changes in public API reviewed

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: timwoj / name: Tim Wojtulewicz (57fbe5a, 5a69527, 0d5fd19, d0b712f)

[codecov]

Codecov Report

Merging #2451 (d0b712f) into main (e79a10f) will not change coverage.
The diff coverage is n/a.

Additional details and impacted files

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  Misses        788      788           

[lalitb]

LGTM. Thanks for the fix.

[marcalff]

Thanks for the fix.

LGTM, see minor renaming.

[marcalff]

@timwoj

Thanks for the fixes.

Please update this branch with the latest main changes.

The auto-merge flag is enabled, this PR should merge to main once updated.

[marcalff]

Reopen.

This collides with the following spec PR, which defines the option and environment variable to use:

• add optional otel_scope_info configuration for prometheus exporter opentelemetry-specification#3796