Provided signature and partial type compatibility with InertiaJS

[juanparati]

I did some rework on the vue-inertia package in order to make it compatible with the original InertiaJS "useForm":

Changes

• Precognition "useForm" will accept object type like InertiaJS:

import {useForm} from 'laravel-precognition-vue-inertia'
const form = useForm<MyInterface>('post', 'https://example.net', mydata);
// or  useForm('post', 'https://example.net', mydata as MyInterface);

• Precognition "useForm" will return the original InertiaJS properties and methods patched with the Precognition properties and methods (I added the types).

• Original interface properties are also exposed.

Advantages of this change

• Original interface properties and Precognition properties and methods are exposed to the linter.
• Better Typescript support.
• Increased signature compatibility with InertiaJS.
• It doesn't require any change in the Precognition core libraries or precognition-vue package.

Disadvantages of this change

• It may require to update the return type in case that original InertiaJS "useForm" method change any of their return properties or method.

[juanparati]

@driesvints: This is a better solution of #64 but also resolves #55.

[juanparati]

Another alternative it's also to the extend the original InertiaForm:

Example:

type FormDataType = object;

interface PrecognitionFormProps<TForm> {
    validating: boolean,                                
    progress: Progress | null;
    reset(...fields: (keyof TForm)[]): this;
    clearErrors(...fields: (keyof TForm)[]): this;
    touched(name: string): boolean,
    touch(name: string | string[] | NamedInputEvent): this;
    submit(submitMethod: RequestMethod|Config, submitUrl?: string, submitOptions?: Partial<VisitOptions>): void;
    setErrors(errors: SimpleValidationErrors|ValidationErrors) : this;
    forgetError(name: string|NamedInputEvent): this;
    setError(field: keyof TForm, value: string): this;
    validate(name?: string|NamedInputEvent): this;
    setValidationTimeout(duration: number): this;
    validateFiles(): this;
    validator(): Validator;
    valid(name: string | NamedInputEvent | string[]): boolean,
    invalid(name: string): boolean,
}

type PrecognitionForm<TForm extends FormDataType> = TForm & PrecognitionFormProps<TForm> & InertiaForm<TForm>;

The advantage is that in case that InertiaJS implement new props it will be inhered, however the disadvantage is that it's not possible to hide non compatible methods and props.

[driesvints]

Thanks @juanparati. Will let @timacdonald review this one.