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[bot]]

The committers listed above are authorized under a signed CLA.

• :white_check_mark: login: aldoKelvianto / name: Aldo Wachyudi (82d3f07173212010d53710fa95d9efc5728c0332)
• :white_check_mark: login: nachoBonafonte / name: Ignacio Bonafonte (8474be3d5554717e5599be10ef6c1d14d5f5d5b1)

[codecov[bot]]

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 :warning:
...s/Stable/Exemplar/HistogramExemplarReservoir.swift	0.00%	2 Missing :warning:
...ntation/URLSession/URLSessionInstrumentation.swift	0.00%	1 Missing :warning:
...Stable/Aggregation/DoubleLastValueAggregator.swift	66.66%	1 Missing :warning:
...rics/Stable/Aggregation/LastValueAggregation.swift	50.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ 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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