Consider removing the materialdesign CDN image dependencies

[E3V3A]

There is no good reason to keep the module having to download the material design icons, every time they are needed. It also prevent the module to display properly if:

• You have firewalled / adblocker not allowing the cdn site
• You do not have an internet connection

Here is the line that does the loading:

  loadCSS: function() {
    var css = [{
        id:   'materialDesignIcons',
        href: 'https://cdn.materialdesignicons.com/2.0.46/css/materialdesignicons.min.css',
    }]

So to accomplish this we need to download the images and keep them in ./images/ (?).
The icons in question are specified here (and possible in other places).

  getDom : function() {
    var wrapper = document.createElement("div")
    wrapper.className = "ASSTNT"
    var iconDom = document.createElement("div")
    iconDom.className = "mdi status " + this.status + " "
    switch(this.status) {
      case 'INITIALIZED':
        iconDom.className += "mdi-microphone-outline"
        break
      case 'HOTWORD_STARTED':
        iconDom.className += "mdi-microphone"
        break
      case 'HOTWORD_DETECTED':
        iconDom.className += "mdi-microphone"
        break
      case 'ASSISTANT_STARTED':
        iconDom.className += "mdi-google-assistant"
        break
      case 'ASSISTANT_SPEAKING':
        iconDom.className += "mdi-google-assistant"
        break
      case 'COMMAND_STARTED':
        iconDom.className += "mdi-apple-keyboard-command"
        break
      case 'COMMAND_LISTENED':
        iconDom.className += "mdi-apple-keyboard-command"
        break
      case 'SPEAK_STARTED':
        iconDom.className += "mdi-message-processing"
        break
      case 'SPEAK_ENDED':
        iconDom.className += "mdi-microphone"
        break
}

[E3V3A]

Two things that need to be done:

1. Download and keep a local copy of the (expanded) but edited css file.
2. Download the icons themselves.

Some content from file is:

/* MaterialDesignIcons.com */
@font-face {
  font-family: "Material Design Icons";
  src: url("../fonts/materialdesignicons-webfont.eot?v=2.0.46");
  src: url("../fonts/materialdesignicons-webfont.eot?#iefix&v=2.0.46") format("embedded-opentype"),
       url("../fonts/materialdesignicons-webfont.woff2?v=2.0.46") format("woff2"),
       url("../fonts/materialdesignicons-webfont.woff?v=2.0.46") format("woff"), 
       url("../fonts/materialdesignicons-webfont.ttf?v=2.0.46") format("truetype"), 
       url("../fonts/materialdesignicons-webfont.svg?v=2.0.46#materialdesigniconsregular") format("svg");
  font-weight: normal;
  font-style: normal;
}
.mdi:before,
.mdi-set {
  display: inline-block;
  font: normal normal normal 24px/1 "Material Design Icons";
  font-size: inherit;
  text-rendering: auto;
  line-height: inherit;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.mdi-access-point:before {
  content: "\F002";
}
...
.mdi-microphone:before {
  content: "\F36C";
}
.mdi-microphone-off:before {
  content: "\F36D";
}
.mdi-microphone-outline:before {
  content: "\F36E";
}