Localize category labels

Added formatMessage to the name attribute for:
* music
* pen
* translate
* video motion

Skipped speak extension - trademarked name
Skipped extensions that are not yet localized at all.

src/extensions/scratch3_music/index.js

@@ -623,7 +623,11 @@ class Scratch3MusicBlocks {
     getInfo () {
         return {
             id: 'music',
-            name: 'Music',
+            name: formatMessage({
+                id: 'music.categoryName',
+                default: 'Music',
+                description: 'Label for the Music extension category'
+            }),
             menuIconURI: menuIconURI,
             blockIconURI: blockIconURI,
             blocks: [

src/extensions/scratch3_pen/index.js

@@ -282,7 +282,11 @@ class Scratch3PenBlocks {
     getInfo () {
         return {
             id: 'pen',
-            name: 'Pen',
+            name: formatMessage({
+                id: 'pen.categoryName',
+                default: 'Pen',
+                description: 'Label for the pen extension category'
+            }),
             blockIconURI: blockIconURI,
             blocks: [
                 {

src/extensions/scratch3_translate/index.js

@@ -86,7 +86,11 @@ class Scratch3TranslateBlocks {
     getInfo () {
         return {
             id: 'translate',
-            name: 'Translate',
+            name: formatMessage({
+                id: 'translate.categoryName',
+                default: 'Translate',
+                description: 'Label for the translate extension category'
+            }),
             menuIconURI: '', // TODO: Add the final icons.
             blockIconURI: '',
             blocks: [

src/extensions/scratch3_video_sensing/index.js

@@ -372,7 +372,11 @@ class Scratch3VideoSensingBlocks {
         // Return extension definition
         return {
             id: 'videoSensing',
-            name: 'Video Motion',
+            name: formatMessage({
+                id: 'videoSensing.categoryName',
+                default: 'Video Motion',
+                description: 'Label for the video motion extension category'
+            }),
             blocks: [
                 {
                     // @todo this hat needs to be set itself to restart existing