[Google Blockly] add field colour plugin

[mikeharv]

When Blockly v11 is release, several field types are being deleted from core and will only be available via plugins: https://github.com/google/blockly/releases/tag/blockly-v11.0.0-beta.4

The one that needs to be addressed is FieldColour which we use for several built-in and custom blocks. This branch adds the plugin and install its built-in blocks, effectively replacing those provided with (v10) core. When we are ready to upgrade this should make things more seamless.

I confirmed that several blocks with color fields are still working as expected and further confirmed that the field methods being used are coming from the plugin source rather than core.

Warning!!

The AP CSP Create Performance Task is in progress. The most critical dates are from April 3 - April 30, 2024. Please consider any risk introduced by this PR that could affect our students taking AP CSP. Code.org students taking AP CSP primarily use App Lab for their Create Task, however a small percent use Game Lab. Carefully consider whether your change has any risk of alterering, changing, or breaking anything in these two labs. Even small changes, such as a different button color, are considered significant during this time period. Reach out to the Student Learning team or Curriculum team for more details.

Links

Jira - https://codedotorg.atlassian.net/browse/CT-490

Testing story

Deployment strategy

Follow-up work

Privacy

Security

Caching

PR Checklist:

• Tests provide adequate coverage
• Privacy and Security impacts have been assessed
• Code is well-commented
• New features are translatable or updates will not break translations
• Relevant documentation has been added or updated
• User impact is well-understood and desirable
• Pull Request is labeled appropriately
• Follow-up work items (including potential tech debt) are tracked and linked