Print the metric list when parsing a prometheus endpoint

[FlorentClarret]

What does this PR do?

Print the metric list when parsing a prometheus endpoint

Motivation

We use this list in the tests

Before:

╰─❯ ddev meta prom parse -f ray_head.txt ray                                                                                                                                                                                                                                                                                                                         ─╯

Globally available options:
    t - Append .total to the available options
    s - Skip
    q - Quit

(1 of 1) python_gc_objects_collected_total
         Type: counter
         Info: Objects collected during gc

1 - python.gc.objects.collected.total
2 - python.gc.objects.collected_total
3 - python.gc.objects_collected.total
4 - python.gc.objects_collected_total
5 - python.gc_objects.collected.total
6 - python.gc_objects.collected_total
7 - python.gc_objects_collected.total
8 - python.gc_objects_collected_total
9 - python_gc.objects.collected.total
10 - python_gc.objects.collected_total
11 - python_gc.objects_collected.total
12 - python_gc.objects_collected_total
13 - python_gc_objects.collected.total
14 - python_gc_objects.collected_total
15 - python_gc_objects_collected.total
16 - python_gc_objects_collected_total
q - Quit
Choose an option (default 16, as-is): 
python_gc_objects_collected_total

Writing `/Users/florent.clarret/go/src/github.com/DataDog/integrations-core/ray/metadata.csv`... success!
METRIC_MAP = {
    'python_gc_objects_collected_total': 'python_gc_objects_collected_total',
}

After:

╰─❯ ddev meta prom parse -f ray_head.txt ray                                                                                                                                                                                                                                                                                                                         ─╯

Globally available options:
    t - Append .total to the available options
    s - Skip
    q - Quit

(1 of 1) python_gc_objects_collected_total
         Type: counter
         Info: Objects collected during gc

1 - python.gc.objects.collected.total
2 - python.gc.objects.collected_total
3 - python.gc.objects_collected.total
4 - python.gc.objects_collected_total
5 - python.gc_objects.collected.total
6 - python.gc_objects.collected_total
7 - python.gc_objects_collected.total
8 - python.gc_objects_collected_total
9 - python_gc.objects.collected.total
10 - python_gc.objects.collected_total
11 - python_gc.objects_collected.total
12 - python_gc.objects_collected_total
13 - python_gc_objects.collected.total
14 - python_gc_objects.collected_total
15 - python_gc_objects_collected.total
16 - python_gc_objects_collected_total
q - Quit
Choose an option (default 16, as-is): 
python_gc_objects_collected_total

Writing `/Users/florent.clarret/go/src/github.com/DataDog/integrations-core/ray/metadata.csv`... success!

METRIC_MAP = {
    'python_gc_objects_collected_total': 'python_gc_objects_collected_total',
}

METRICS = [
    'python_gc_objects_collected_total',
]

Additional Notes

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• Changelog entries must be created for modifications to shipped code
• Add the qa/skip-qa label if the PR doesn't need to be tested during QA.

[github-actions]

Test Results

    4 files      4 suites   4m 5s ⏱️
418 tests 418 ✔️   0 💤 0 ❌
936 runs  903 ✔️ 33 💤 0 ❌

Results for commit 971dadd.

♻️ This comment has been updated with latest results.

[codecov]

Codecov Report

Merging #15586 (971dadd) into master (14a02fc) will increase coverage by 0.00%.
The diff coverage is n/a.

Flag	Coverage Δ
datadog_checks_dev	82.51% <ø> (+0.07%)	⬆️

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[buraizu]

Thanks, approving with a minor update to the changelog