Allow Step#spec to be a generic to give a data constraint to spec handlers

[jmcdo29]

Hey there! Been loving using Pactum for some E2E tests recently, working on a full example suite using PactumJS, NestJS, and uvu! I've noticed that there's times I'd like to have my named specs pass in structured data, but right now pactum types that as any. I was hoping you wouldn't mind a small PR to update the step.d.ts file to set Step#spec to be typed as

declare class Step {
  spec<T = any>(name?: string, data?: T): StepSpec;
  clean(name?: string, data?: any): CleanStep;
  toss(): Promise<void>;
}

This shouldn't bring in any breaking changes, as the type by default is still any, but now I could do something like

NeighborSuite('Add another neighborhood', async ({ neighborE2E }) => {
  const anotherNeighborhoodStep = neighborE2E.step('Add Another Neighborhood');
  await anotherNeighborhoodStep
    .spec<{ key: string; overrides: Record<string, string> }>( // <---- the generic right here gives stricter typings for the second parameter
      NeighborhoodConstants.specs.add,
      {
        key: 'NewNeighborhood',
        overrides: {
          name: 'NewNeighborhood',
          location: 'N',
        },
      },
    )
    .toss(),
    anotherNeighborhoodStep.clean(NeighborhoodConstants.specs.delete, {
      id: `$S{NewNeighborhood${NeighborhoodConstants.keys.id}}`,
    });
});

And have stricter typings for the data passed into the spec()

[ASaiAnudeep]

Hey @jmcdo29, thank you for the suggestion. If it's not going to break anything, we can extend the same behaviour to the rest of the library.

Please raise a PR with the changes.

[jmcdo29]

Pull request issued: #136