Adapt logger for kuma integration

[Gldywn]

## Description

This PR introduces a flexible logging system to allow users to integrate their own logging solutions and customize log output formats. The previous `LogSink` interface was rigid and did not easily support integration with external loggers, such as the one used by Uptime Kuma.

The new system replaces `LogSink` with a `LogAdapter` function, which accepts a structured `LogObject`. This enables consumers of the library to provide a custom function to process log messages, allowing for seamless integration with any logging framework and full control over the log message format. The `HardenedHttpsValidationKit` now accepts an optional `logAdapter` in its options.

## Related Issue

N/A

## Type of Change

- [ ] Bug fix (non-breaking change which fixes an issue)
- [x] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
- [x] This change requires a documentation update

## Checklist

- [x] I have read the [CONTRIBUTING.md](./CONTRIBUTING.md) file.
- [x] I have performed a self-review of my own code.
- [x] I have commented my code, particularly in hard-to-understand areas.
- [x] I have made corresponding changes to the documentation.
- [x] My changes generate no new warnings.
- [ ] I have added tests that prove my fix is effective or that my feature works.
- [x] New and existing unit tests pass locally with my changes.
- [ ] Any dependent changes have been merged and published in downstream modules.

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Codecov Report

❌ Patch coverage is 91.66667% with 1 line in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/validation-kit.ts	85.71%	1 Missing ⚠️

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