Add inline Test CodeLens for per-test execution in source editor

[Omotola]

Overview

Implements inline "Run" and "Debug" CodeLens buttons directly in C++ source files, enabling users to execute individual tests from the editor gutter without running all tests. Resolves #4451.

Changes

• New File: src/ui/testCodeLensProvider.ts — Provides CodeLens UI for test locations
• Enhanced: src/ctest.ts — Improved test source location resolution with 3-tier priority:
  1. CMake metadata (DEF_SOURCE_LINE property)
  2. Code model executable→sources mapping
  3. Fallback doctest parsing with fuzzy token matching
• Integrated: src/extension.ts — Wired CodeLens provider and per-test command handlers
• Localized: package.nls.json — Added UI strings for CodeLens labels

Key Improvements

• Robust doctest parsing: Supports TEST_CASE(), SCENARIO(), TEMPLATE_TEST_CASE() macros with raw string literals (R"...")
• Fuzzy name matching: Normalized test name comparison handles scenario prefixes and bracket tags [...]
• Per-test execution: Commands cmake.runTestFromCodeLens and cmake.debugTestFromCodeLens route to single test instead of all tests
• Accurate line ranges: Test items properly assigned per-line ranges for cursor-based VS Code test commands

Testing

• ✅ Feature validated with doctest framework
• ✅ Single-test execution working correctly
• ✅ Source location resolution handles edge cases
• ✅ No TypeScript diagnostics errors

Validation

Notes

• Feature respects existing cmake.testExplorerIntegrationEnabled setting
• Works in both CMake Presets and Kits/Variants modes
• Compatible with single-config and multi-config generators