Added "createPaginationMeta" helper function for manual creation of pagination meta

[adrians5j]

This can be used to manually create pagination meta.

Example:

import { createPaginationMeta } from "webiny-entity";

let meta = createPaginationMeta({
    page: 1,
    perPage: 10,
    totalCount: 100
});

[coveralls]

Coverage decreased (-0.04%) to 94.928% when pulling eec6a1d on createPaginationMeta into 97b014d on development.