[CODE HEALTH] Fix clang-tidy special-member-functions warnings in trace API

[dbarker]

Contributes to #2053

Fixes cppcoreguidelines-special-member-functions warnings in opentelemetry/trace

Changes

Fixes the following warnings:

cppcoreguidelines-special-member-functions (5 warnings)

File	Line	Message
opentelemetry-cpp/api/include/opentelemetry/trace/default_span.h	21	class 'DefaultSpan' defines a copy constructor and a move constructor but does not define a destructor, a copy assignment operator or a move assignment operator
opentelemetry-cpp/api/include/opentelemetry/trace/span_context.h	24	class 'SpanContext' defines a copy constructor and a copy assignment operator but does not define a destructor, a move constructor or a move assignment operator
opentelemetry-cpp/api/include/opentelemetry/trace/span_context_kv_iterable.h	18	class 'SpanContextKeyValueIterable' defines a default destructor but does not define a copy constructor, a copy assignment operator, a move constructor or a move assignment operator
opentelemetry-cpp/api/include/opentelemetry/trace/tracer.h	27	class 'Tracer' defines a default destructor but does not define a copy constructor, a copy assignment operator, a move constructor or a move assignment operator
opentelemetry-cpp/api/include/opentelemetry/trace/tracer_provider.h	21	class 'TracerProvider' defines a default destructor but does not define a copy constructor, a copy assignment operator, a move constructor or a move assignment operator

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

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.06%. Comparing base (4307862) to head (be9f99f).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3934      +/-   ##
==========================================
+ Coverage   90.06%   90.06%   +0.01%     
==========================================
  Files         226      226              
  Lines        7227     7229       +2     
==========================================
+ Hits         6508     6510       +2     
  Misses        719      719              

Files with missing lines	Coverage Δ
api/include/opentelemetry/trace/default_span.h	18.75% <100.00%> (+5.42%)	⬆️
api/include/opentelemetry/trace/span_context.h	100.00% <ø> (ø)
...ude/opentelemetry/trace/span_context_kv_iterable.h	100.00% <100.00%> (ø)
api/include/opentelemetry/trace/tracer.h	100.00% <100.00%> (ø)
api/include/opentelemetry/trace/tracer_provider.h	100.00% <100.00%> (ø)

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[marcalff]

Looks good, just one question.

[marcalff]

LGTM, thanks for the cleanup.