Fix Typos and and Minor Code Adjustments

[aldoKelvianto]

This pull request tries to improve the opentelemetry-swift project's documentation by correcting spelling mistakes and making minor readability enhancements in various source and test files.

An example of these corrections is in the OpenTelemetryApi, which is frequently read by SDK users. For instance, upon reviewing the SpanKind enum, I noticed that the letter I in Indicates was missing.

Thank you for considering these adjustments.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: aldoKelvianto / name: Aldo Wachyudi (82d3f07)
• ✅ login: nachoBonafonte / name: Ignacio Bonafonte (8474be3)

[nachoBonafonte]

LGTM, thanks a lot for your contribution.

[codecov]

Codecov Report

Attention: 8 lines in your changes are missing coverage. Please review.

Comparison is base (297d91f) 66.34% compared to head (8474be3) 66.34%.

Files	Patch %	Lines
...s/Stable/Aggregation/LongLastValueAggregator.swift	0.00%	3 Missing ⚠️
...s/Stable/Exemplar/HistogramExemplarReservoir.swift	0.00%	2 Missing ⚠️
...ntation/URLSession/URLSessionInstrumentation.swift	0.00%	1 Missing ⚠️
...Stable/Aggregation/DoubleLastValueAggregator.swift	66.66%	1 Missing ⚠️
...rics/Stable/Aggregation/LastValueAggregation.swift	50.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #515   +/-   ##
=======================================
  Coverage   66.34%   66.34%           
=======================================
  Files         336      336           
  Lines       14466    14466           
=======================================
  Hits         9597     9597           
  Misses       4869     4869           

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