Enable execute tests to run on Windows

- Removing the `@TestOn('!windows')` annotation that excluded all tests
from Windows
- Adding new tests for working directory, stderr streaming, and complex
shell commands that work on both platforms
- Skipping only the SIGINT forwarding test on Windows (bash `trap` has
no Windows equivalent, and `Process.kill(ProcessSignal.sigint)` doesn't
trigger signal handlers on Windows anyway)
- Fixing `echo "Hello world!"` to `echo Hello world!` for cross-platform
compatibility
- Implementing `MockStdout.addStream()` to support the new tests

This PR adds:
- Support for PostHog analytics.
- Support for `CompoundAnalytics` - the ability to combine multiple
providers into a single one.
- More detailed analytics (the full command, with any free form text
parameters masked).

Breaking change:
`OnAnalyticsEvent` now requires an additional `properties` parameter.

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
  * Support for multiple analytics providers (Mixpanel, PostHog).
* Analytics events include enriched, sanitized command-context
properties.
  * Analytics API adds user identification capability.

* **Breaking Changes**
* Analytics callback/API now receives an additional properties argument
when events are emitted.

* **Tests**
* Added unit tests validating command-property masking and full-command
composition for analytics.

<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **Enhancements**
* Analytics tracking now supports configurable per-instance library
names, enabling greater flexibility in multi-instance deployments.

<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Packages:
- cli_tools v0.11.0
- config v0.8.4


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **New Features**
  * Added PostHog analytics integration
  * Made library name configurable in analytics settings

* **Bug Fixes**
  * Improved OptionResolution interface accessibility

<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>

<!-- end of auto-generated comment: release notes by coderabbit.ai -->