Zoom reset not centering workspace

[alschmiedt]

Describe the bug
The reset zoom button does not center the workspace anymore.

To Reproduce

Steps to reproduce the behavior:

1. Go to https://google.github.io/blockly/tests/playground.html
2. Drag some blocks on to the workspace.
3. Move the workspace around.
4. Hit the reset zoom button
5. Notice how nothing happens.
   Expected behavior
   The workspace should center itself.

Screenshots

Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Stack Traces

Replace with error stack trace.

Additional context

[moniika]

Fixed by #4725