[CodeHealth] Fix clang-tidy warnings part 5

[dbarker]

Contributes to #2053

Changes

Fixes clang-tidy warnings with the OTLP File component

• cppcoreguidelines-slicing
• cppcoreguidelines-avoid-const-or-ref-data-members
• cppcoreguidelines-special-member-functions

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

[netlify]

✅ Deploy Preview for opentelemetry-cpp-api-docs canceled.

Name	Link
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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.96%. Comparing base (dff39f3) to head (24d7bef).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3506   +/-   ##
=======================================
  Coverage   89.96%   89.96%           
=======================================
  Files         219      219           
  Lines        7051     7051           
=======================================
  Hits         6343     6343           
  Misses        708      708           

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[marcalff]

LGTM

[marcalff]

According to CI, this solves only 1 warning (85 instead of 86).

To reevaluate once part 4 is merged.

[dbarker]

According to CI, this solves only 1 warning (85 instead of 86).

To reevaluate once part 4 is merged.

Yes. It may be due to using an older version of clang-tidy in CI. So we won't see the satisfying drop in warnings from this but they do need to be fixed. :)

I found the warnings using the clangd extension to vscode while fixing the slicing warning. CI only reports the slicing warning for some reason.