Add function versions of all formatters for simpler syntax

[henriquemoody]

Summary

Add function versions of all formatters to provide a simpler, more ergonomic API for common formatting tasks.

Usage Example

Instead of writing:

new PlaceholderFormatter(['foo' => true, 'bar' => [1, 2, 3]])->format('{{foo}} must be {{bar|list:or}}')

Users should be able to write:

formatter_placeholder('{{foo}} must be {{bar|list:or}}', ['foo' => true, 'bar' => [1, 2, 3]])

Desired Behavior

Create standalone functions for each formatter type that wrap the existing builder pattern, making the API more concise for common use cases.

Acceptance Criteria

• Add function versions for all formatters
• Functions should accept format string and any scalar value
• Include tests for new functions