[PROF-7440] Add workaround for incorrect invoke location when logging gem is in use

[ivoanjo]

What does this PR do?

In #2950, we added a fallback for nameless threads: we use their "invoke location", as shown by Ruby in the default Thread#to_s. The invoke location is the file and line of the first method of the thread.

This fallback has an issue: when thread creation is monkey patched. One common source of this is the logging gem. When the logging gem monkey patches thread creation, every thread will have the same invoke location, which will point to the logging gem.

This made the fallback invoke location worse than not having anything.

To work around this, this PR changes the profiler so that when the invoke location belongs to the logging gem, it's not used, and a simpler (Unnamed thread) placeholder is used instead.

Motivation:

This issue came up when testing the timeline feature with some of the internal Ruby apps.

Additional Notes:

In the future we could probably explore a more generic fix (e.g. using Thread.method(:new).source_location or something like that to detect redefinition) but doing that from the profiler native code is a bit more work so I decided to go with a simpler approach.

How to test the change?

Change includes test coverage. You can also see the thread name difference on an app by creating a simple thread before/after loading the logging gem and see the fallback name for the thread.

For Datadog employees:

• If this PR touches code that signs or publishes builds or packages, or handles
  credentials of any kind, I've requested a review from @DataDog/security-design-and-guidance.
• This PR doesn't touch any of that.

[codecov-commenter]

Codecov Report

Merging #3183 (1cde833) into master (c8de363) will increase coverage by 0.00%.
Report is 10 commits behind head on master.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #3183   +/-   ##
=======================================
  Coverage   98.21%   98.21%           
=======================================
  Files        1247     1248    +1     
  Lines       71664    71685   +21     
  Branches     3329     3330    +1     
=======================================
+ Hits        70382    70403   +21     
  Misses       1282     1282           

Files	Coverage Δ
...iling_native_extension/native_extension_helpers.rb	96.73% <100.00%> (ø)

... and 5 files with indirect coverage changes

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[ekump]

A hacky solution, but LGTM to unblock the 1.15 release. This is better than no fix at all. Might be worth adding a comment to the code indicating that it's likely a temporary solution?

[ivoanjo]

A hacky solution, but LGTM to unblock the 1.15 release. This is better than no fix at all. Might be worth adding a comment to the code indicating that it's likely a temporary solution?

Thanks for the review + agreed. Documented it in 4ff3cf6.