Make PromptBuilder::isSupported public #128
Description
There's no good reason to keep this method private. generateResult, which is the equivalent for actual generation is already public. That method is useful when approaching things from a truly multimodal perspective, and we should allow checking for support to work similarly.
Last but not least: Making this public will avoid ugly conditionals like this one: https://github.com/WordPress/wp-ai-client/pull/27/files#diff-6ffc16c3dfbbfc9f75adef72902d8024ef48815359fceae974734c847112e409R160