Test Fluent.js for complex accessibility strings

[jessegreenberg]

After #990, we are going to try Fluent.js to support i18n for complex accessibility strings.

In this issue Ill track changes and progress. First, we are going to bring Fluent in as a dependency. Then, we are going to try it out with 3 sims. We are then going to test the strings with translators to get feedback.

EDIT: I have a growing list of branches in repos as we do this work. Collected in this coment: #992 (comment)

[jessegreenberg]

The latest version of Fluent.js was not compatible with our preload system/sherpa which requires a standalone built file. We found a build in this format at https://www.npmjs.com/package/fluent. It is 5 years old.

We will want to figure out how we can get the latest version. For other POSE reasons, PhET is exploring how we can use a more standard way of importing dependencies. But if that isn't figured out, we will need to find a way to bundle a more recent version of Fluent so it can be used in sherpa.

[jessegreenberg]

The above commits complete a first pass at using Fluent in ohms-law for accessibility strings.

[jessegreenberg]

I am making a branch in chipper called fluent to hold preloads and utility classes that are supporting this work. See #1532.

[jessegreenberg]

GFL:B is proving to be too time consuming for this test because of the complicated string patterns. Strings are factored out and reassembled with code in a way that is good for English but is not friendly for i18n. We are going to switch to MaL instead.

[jessegreenberg]

List of repo branches so far to support this work:

• chipper fluent - With classes and utility functions for working with fluent messages, and as Properties for dynamic locales.
• ohms-law fluent - Sim implementation.
• greenhouse-effect fluent - Sim implementation for molecules-and-light (molecules-and-light code lives in greenhouse-effect)
• molecules-and-light fluent- Preloads for fluent need to be defined in its package.json, even though it pulls from greenhouse-effect.
• perennial fluent - TypeScript in chipper requires Fluent files to be declared in this file.

[jessegreenberg]

The above commits complete a first pass at using Fluent in molecules-and-light for accessibility strings.