Spike for expression language evaluation in display names

[jean-andre-gauthier]

Overview

• Introduces a new @ExpressionLanguage annotation, that takes a Class<ExpressionLanguageAdapter> as parameter
• Introduces a new ExpressionLanguageAdapter interface, that can be implemented to bind in a third-party expression language
• Adds several tests in ExpressionLanguageMustacheTests, that demonstrate how @ExpressionLanguage / ExpressionLanguageAdapter can be used

I'm marking this as a draft PR, because it's not entirely clear yet how the API should look like. I'll address the items in the Definition of Done once we have more clarity on that.

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Definition of Done

• There are no TODOs left in the code
• Method preconditions are checked and documented in the method's Javadoc
• Coding conventions (e.g. for logging) have been followed
• Change is covered by automated tests including corner cases, errors, and exception handling
• Public API has Javadoc and @API annotations
• Change is documented in the User Guide and Release Notes

[jean-andre-gauthier]

This is not correct, but I'm unsure how we should name multiple arguments, so that they can be accessed by the EL?

[sbrannen]

I've only taken a quick glance, but for starters...

This new feature must be applicable to JUnit Jupiter in general, not just for parameterized tests.

So the APIs need to reside in the junit-jupiter-api module.

Please revise your work to take that into account.

See also: #1154 (comment)