issue #2683 : Naming Scheme metadata and TableView apply toolbar

[mattcasters]

Summary

Implements a first cut of Naming Scheme metadata for issue #2683: reusable rules to normalize Hop field names (spaces → underscores/dashes, camelCase, PascalCase, lower/upper case, etc.), applied from a new TableView toolbar action.

• New plugin plugins/misc/naming (hop-misc-naming): metadata type, editor with live preview, pure NamingEngine, unit tests
• TableView toolbar: pick column + Naming Scheme (type Hop field names) → rewrite non-empty cells with undo via TableView.applyColumnValues
• Scheme types reserved for follow-up: database tables, database columns, files, folders
• User manual page with screenshots

How to try

1. Create a Naming Scheme in the Metadata perspective (default options give e.g. Order ID → order_id)
2. Open any editable field table (CSV File Input fields works well)
3. Click Apply a Naming Scheme to a column on the TableView toolbar
4. Select column + scheme → values update; Undo reverts

Feedback wanted

This is a draft to gather community input on where else Naming Schemes should land next. Please weigh in on:

1. Database explorer — rename tables / columns with dialect-aware rules (length, reserved words)?
2. File Explorer — bulk rename files / folders (illegal path chars, extensions)?
3. Transform “Get fields” — optional scheme reference so input transforms auto-normalize discovered names?
4. Other surfaces — mapping dialogs, static schema editor, Beam file definition, Data Vault / modeling plugins?
5. Scheme model — are the current options (case style, separator, strip specials, prefix/suffix) enough, or do we need presets / more rules?

Test plan

• NamingEngineTest (13 cases) passes
• Module + core/ui build succeeds; Spotless clean
• Manual: create scheme, apply from CSV File Input field list, undo
• Manual: verify metadata appears under Data definition category

Fixes #2683