Add smart stepping to skip unmapped generated code during stepping

[Copilot]

This PR adds feasibility-proven smart stepping support so stepping no longer gets stuck in transpiler/generated code that is not mapped back to user source. It also handles the roku-debug one-to-one remap case (no sourcemap present) as uninteresting code to step through.

• Launch configuration

  • Added smartStep?: boolean to LaunchConfiguration.
  • Wired default normalization (false) in BrightScriptDebugSession.

• Smart-step control flow in debug session

  • Added pending-step tracking for next, stepIn, and stepOut.
  • On suspend, when smartStep is enabled:
    • Detects whether the current generated line is “interesting” (mapped) or “uninteresting” (unmapped).
    • Automatically issues another step for uninteresting lines.
    • Emits StoppedEventReason.step once a mapped/interesting location is reached.
  • Clears smart-step state on continue/pause/restart and includes a max-attempt guard to prevent loops.

• Source map line-coverage detection

  • Added SourceMapManager.generatedLineIsMapped(filePath, generatedLineNumber).
  • Uses source map mapping entries (generated-order) to determine whether a generated line is explicitly covered by mappings.
  • Caches mapped-line sets per sourcemap path.

• No-sourcemap remap behavior

  • If no sourcemap exists for the staged file, smart-step checks whether getSourceLocation resolves to a different source file.
  • If so, it treats the current line as generated/uninteresting and keeps stepping (matching the requested one-to-one remap behavior).

// launch.json
{
  "type": "brightscript",
  "request": "launch",
  "smartStep": true
}