fix: keyboard navigation tests

[rachel-fenichel]

The changes

Actual keyboard nav implementation: Adjust how it's calling a superclass function in a strange bit of monkeypatching code. This change is necessary because of the switch to ES6 classes.

Test code:

• Stop overriding Blockly.utils.dom.getFastTextWidthWithSizeString.
  • This is no longer accessible for replacement. Unfortunately, without this monkeypatch, the tests fail any time they try to render a field with text that has to be measured.
• Replace text fields with colour fields in test blocks.
  • Colour fields can render just fine, because they don't need text width measurement. The fields are mostly used to test that the correct block has been selected after a series of key presses. That happens by looking at the value of the field, which is set in the hardcoded toolbox definition. I updated the block definitions, toolbox definitions, and test assertions to all be for my colour fields.
• Don't access a private field in MarkerManager for a test assert. Particularly since that field's name has changed. Use the getter instead.
• Call this.navigation.removeWorkspace(this.workspace) in the test teardown for each suite. Otherwise the workspace is disposed before being removed from this.navigation, which means that the navigation object is manipulating an already-disposed WorkspaceSvg object.
  • I'm not sure why this worked before.

Tested

In the keyboard nav playground and with automated tests.