Autopagination does not throw backend errors appropriately

[sofisl]

Investigating: https://github.com/googleapis/nodejs-datacatalog/issues/296

It seems like, when autoPagination is on, and you throw an error, it does not stop getting resources. To reproduce:

1. call searchAssets.js in datacatalog (datacatalog has a lot of resources, we're trying to get a large response):

'use strict';

async function main(projectId) {
  // [START data_catalog_search_assets]
  // Import the Google Cloud client library.
  const {DataCatalogClient} = require('@google-cloud/datacatalog').v1;
  const datacatalog = new DataCatalogClient();

  async function searchAssets(projectId) {
    // Search data assets.

    /**
     * TODO(developer): Uncomment the following lines before running the sample.
     */
    // const projectId = 'my_project'; // Google Cloud Platform project

    // Create request.
    const scope = {
      includeProjectIds: [projectId],
      // Alternatively, search using Google Cloud Organization scopes.
      //includeOrgIds: ["google.com"],
    };

    const request = {
      scope: scope,
      pageSize: 50,
      includeGcpPublicDatasets: true,
      orderBy: 'relevance',
    };

    const [result] = await datacatalog.searchCatalog(request);

    console.log(`Found ${result.length}`);
    console.log('Datasets:');
    result.forEach(dataset => {
      console.log(dataset.relativeResourceName);
    });
  }
  searchAssets();
  // [END data_catalog_search_assets]
}
main(...process.argv.slice(2));

Then, in gax (in pagedApiCaller.ts, https://github.com/googleapis/gax-nodejs/blob/2217633d95b49279a3d00fa7b720443d89ab3086/src/paginationCalls/pagedApiCaller.ts#L91):

Add a global counter, and these statements:

            counter++;
            callback(err, resources, nextPageRequest, response);
            if (counter === 5) { const err = new googleError_1.GoogleError('error'); err.code = 8; /* resource exhausted */ callback(err); return; }

It will continue grabbing pages indefinitely.

In addition to fixing this bug, we should add unit tests here.