Provide bang versions of meta methods

[atomaka]

Fixes #202

What is the purpose of this pull request?

Provide Logidze.with_meta! and Logidize.with_responsible! to attach these details permanently instead of for the duration of a block. This resolves #202 and allows the behavior outlined in #200:

console do
  Logidze.with_responsible(current_user.id)
end

It also considers feedback in the attempt from #203.

Finally, this resolves #221, although using this in web requests comes with its own risks.

What changes did you make? (overview)

In Logidze::Meta

• New class MetaBase pulling meta stack management from MetaWrapper
• New class MetaForConnection to manage metadata for bang methods
• New method .with_meta! to set metadata with no implicit end
• New method .with_responsible! to set actor id with no implicit end
• New method .clear_meta! to explicitly clear metadata

Is there anything you'd like reviewers to focus on?

I'm not sure how I feel about this implementation so I'm happy to revisit it if there are suggestions. I believe i hit the use-cases missed in #203.

Changelog/Readme changes will be added after the approach has been established.

Checklist

• I've added tests for this change
• I've added a Changelog entry
• I've updated a documentation (Readme)

[palkan]

I'm not sure how I feel about this implementation

Me neither. But that's an old problem with the whole meta.rb, so let's not bother about it now.

Thanks!