Route results through Recorder and bundle core reporters

[trans]

Summary

• Route completed outcomes through Test::Result and Test::Recorder, with finish(summary) for reporters.
• Bring summary, outline, progress, and TAP 13 formats into the main gem. Formats load only when selected.
• Remove the old Recorder callback/table adapter, preserve multiple test and hook exceptions, and ensure bundled formats win over old formatter gems on the load path.
• Capture test output for TAP diagnostics and count skipped or broken cases in the final plan.

Prerequisite

#8 is merged. This PR now targets master and contains only the Result/Recorder and reporter changes.

Verification

• bundle exec rake test: 5 demos, 33 steps, 85 assertions, no failures or errors.
• prove --exec 'ruby -Ilib bin/rubytest -f tap' test/basic_case.rb: passes.
• Facets full suite with this RubyTest checkout: 1,261 passing, 4 pending, 6 skipped.
• Verified an old rubytest-summary on RUBYLIB cannot shadow the bundled formatter.