[Logger] Add structured log context filtering

[RedZapdos123]

Description:

Issue #370 asked for a built-in way to filter sensitive values from Rage's structured log context.

This PR adds config.filter_parameters, which applies Rails-style case-insensitive partial matching to structured context keys and replaces matching values with [FILTERED] before the log entry is written.

The implementation stays inside Rage's own logger code and applies consistently to with_context, inline logger context, request log context added through append_info_to_payload, global config.log_context, and dynamic external logger context payloads.

As discussed in the issue, this PR only filters structured context. It does not change request_info.

It also adds regression specs for logger filtering, configuration wiring, nested structured context, and the unchanged request_info behavior for dynamic external loggers.

Closes #370.

Checklist:

• I have added relevant regression test cases for this change.
• I have run linting checks using bundle exec rubocop lib/rage/logger/logger.rb lib/rage/configuration.rb spec/logger_spec.rb spec/configuration_spec.rb.
• I have run focused specs using bundle exec rspec spec/logger_spec.rb spec/configuration_spec.rb.
• I have run syntax checks using bundle exec ruby -c lib/rage/logger/logger.rb && bundle exec ruby -c lib/rage/configuration.rb.

Before the fix:

Sensitive keys in structured log context were written as-is.

Rage did not have a built-in filtering mechanism for with_context, inline logger context, or request log context merged through append_info_to_payload.

Example:

[my_test_tag] timestamp=... level=info password_confirmation=secret AUTH_TOKEN=abc user_id=12345 message=passed

After the fix:

config.filter_parameters filters matching structured context keys before log emission.

Matching is case-insensitive and partial, so keys like password_confirmation and AUTH_TOKEN are filtered.

Nested hashes and arrays are filtered recursively.

Dynamic external loggers receive filtered context and unchanged request_info.

Example:

[my_test_tag] timestamp=... level=info password_confirmation=[FILTERED] AUTH_TOKEN=[FILTERED] user_id=12345 message=passed