Add Users.setInjectorGain() and Users.getInjectorGain() to the scripting interface

libraries/script-engine/src/UsersScriptingInterface.cpp

@@ -51,6 +51,15 @@ float UsersScriptingInterface::getAvatarGain(const QUuid& nodeID) {
     return DependencyManager::get<NodeList>()->getAvatarGain(nodeID);
 }
 
+void UsersScriptingInterface::setInjectorGain(float gain) {
+    // ask the NodeList to set the audio injector gain
+    DependencyManager::get<NodeList>()->setInjectorGain(gain);
+}
+
+float UsersScriptingInterface::getInjectorGain() {
+    return DependencyManager::get<NodeList>()->getInjectorGain();
+}
+
 void UsersScriptingInterface::kick(const QUuid& nodeID) {
 
     if (_kickConfirmationOperator) {

libraries/script-engine/src/UsersScriptingInterface.h

@@ -97,6 +97,21 @@ public slots:
     */
     float getAvatarGain(const QUuid& nodeID);
 
+    /**jsdoc
+     * Sets the audio injector gain at the server.
+     * Units are Decibels (dB)
+     * @function Users.setInjectorGain
+     * @param {number} gain (in dB)
+    */
+    void setInjectorGain(float gain);
+
+    /**jsdoc
+     * Gets the audio injector gain at the server.
+     * @function Users.getInjectorGain
+     * @returns {number} gain (in dB)
+    */
+    float getInjectorGain();
+
     /**jsdoc
      * Kick/ban another user. Removes them from the server and prevents them from returning. Bans by either user name (if 
      * available) or machine fingerprint otherwise. This will only do anything if you're an admin of the domain you're in.