Update monitor labels on the stage when language changes

A complete rewrite of OpcodeLabels. Instead of function, it’s a class that maintains a current translator function, and updates the opcode labelFn for each opcode when a new translator function is set. Add function `getLabel` to return the object with `category` and `labelFn` based on the opcode.

Set intl.formatMessage as the translator function in MonitorList. It has access to the intl object, and wraps all monitors.

chore(package): update scratch-paint to version 0.2.0-prerelease.2018…

Update scratch-vm to the latest version 

Update scratch-storage to the latest version 

Update react-contextmenu to the latest version 

Update file-loader to the latest version 

Closes #3325

chore(package): update scratch-blocks to version 0.1.0-prerelease.153…

Update scratch-vm to the latest version 

Closes #3312

* Translate "(empty)" and "length {value.length}"
* Use FormattedMessage

added micIndicator prop validation

chore(package): update scratch-vm to version 0.2.0-prerelease.2018100…

Fix sprite-info pane for ‘wide’ languages

Closes #3308

Change Cards Close ID

Update scratch-l10n to the latest version 

Update scratch-blocks to the latest version 

Update scratch-storage to the latest version 

Update scratch-render to the latest version 

Update scratch-vm to the latest version 

Fix alerts component/containers and CSS styling