fix: omit JsonValue type if not used

[joshhunt]

This PR

If you don't use flags with the object type, the React generator will make code that contains errors/warnings that the JsonValue import is unused. This PR fixes that by only including the JsonValue import if it is needed by object flags.

• fixes the React and Angular generator to omit the JsonValue type if not used
• fixes the React generator to use the type import type for JsonValue

[gemini-code-assist]

Code Review

This pull request implements conditional imports for the JsonValue type in Angular and React generators, ensuring it is only included when 'object' flags are defined. It introduces a HasFlagType method to the Flagset struct and adds corresponding test cases and golden files. Feedback was provided to improve the HasFlagType method by using enum comparisons and adding a nil check for better robustness.

[gemini-code-assist]

The HasFlagType method currently relies on a direct string comparison with the output of f.Type.String(). This is somewhat fragile as it requires the caller to know the exact string representation used internally (e.g., "object" vs "Object").

It would be more robust and efficient to use the existing ParseFlagType function to convert the input string to a FlagType enum once, and then compare the enums in the loop. This also allows the method to support aliases (like "JSON" for objects) and case-insensitivity, consistent with how flags are parsed from the manifest. Additionally, adding a check for a nil receiver prevents potential panics.

func (fs *Flagset) HasFlagType(typeName string) bool {
	if fs == nil {
		return false
	}
	t, err := ParseFlagType(typeName)
	if err != nil {
		return false
	}
	for _, f := range fs.Flags {
		if f.Type == t {
			return true
		}
	}
	return false
}