RE1-T115 Adding TTS service to handle multi-lingual support for voice.

[ucswift]

Summary by CodeRabbit

• New Features

  • Full TTS microservice added (generation, playback URLs, admin regeneration, warmup)
  • Voice call flows and verification now use generated speech; per-department TTS language selectable in settings
  • Audio caching and playback endpoints for improved performance; scoped rate-limiting for TTS requests

• Infrastructure

  • Docker, Kubernetes manifests and solution/project updates for TTS service
  • Multi-target build support added (net8.0 and net9.0)

• Tests

  • Extensive unit/integration tests for TTS, playback, storage, and voice response behaviors