Feat/ambient sounds (#678)

* initial support for coaching mode in conference

* wip

* wip

* add support for answer verb

* wip

* wip

* wip

* wip

* wip

* updates to rename option to dub

* wip

* wip

* wip

* update verb-specs

* wip

* wip

* wip

* wip

* wip

* wip

* wip

* wip

* add option to boost audio signal in main channel

* wip

* wip

* wip

* wip

* wip

* wip

* for now, bypass use of streaming apis when generating tts audio for dub tracks

* add nested dub to dial

* wip

* add support for filler noise

* kill filler noise when gather killed

* wip

* wip

* while using sayOnTrack, we have to enclose the say command in double quotes

* disableTtsStreaming = false

* allow transcribe of b leg only on dial verb

* dub.say can either be text or object like say verb with text and synthesizer

* remove loop for sayOnTrack

* update speech-utils

* fixes for testing transcribe verb and support for dub and boostAudioSignal in lcc commands

* add dial.boostAudioSignal

* fix bug where session-level recognizer settings incorrectly overwrite verb-level settings

* update verb specs

* update dial to support array of dub verbs

* fix bug setting gain

* lint

* wip

* update speech-utils

* use new endpoint methods for mod_dub

---------

Co-authored-by: Dave Horton <daveh@beachdognet.com>

lib/tasks/answer.js

@@ -0,0 +1,22 @@
+const Task = require('./task');
+const {TaskName, TaskPreconditions} = require('../utils/constants');
+
+/**
+ * Answer the call.
+ * Note: This is rarely used, as the call is typically answered automatically when required by the app,
+ * but it can be useful to force an answer before a pause in some cases
+ */
+class TaskAnswer extends Task {
+  constructor(logger, opts) {
+    super(logger, opts);
+    this.preconditions = TaskPreconditions.Endpoint;
+  }
+
+  get name() { return TaskName.Answer; }
+
+  async exec(cs) {
+    super.exec(cs);
+  }
+}
+
+module.exports = TaskAnswer;