feat: support array and object input with messageParams and cause (#117)

[Ankitraj-sharma]

Summary

Closes #117.

This PR improves parameter handling for FastifyError instantiation as discussed in #117:

1. Array input support: Allows passing an array of parameters to format strings with multiple specifiers (e.g. new CustomError(['foo', 'bar'])).
2. Object input support: Implements the proposal to allow passing an object containing { messageParams, cause } directly (e.g. new CustomError({ messageParams: ['foo', 'bar'], cause: new Error('...') })).
3. Format specifier counting: Added helper countFormatSpecifiers to determine expected formatting arguments while respecting escaped %% specifiers.
4. Backward compatibility: Preserves existing variable arguments and options patterns without breaking existing tests or consumers.

Testing

• Added unit tests for array of parameters.
• Added unit tests for object input with messageParams and cause.
• Added unit tests for object input with only cause when format parameters exist.
• All 32 unit tests pass.

[gurgunday]

Hi, thanks for the PR but we currently have #151 which is already under review