Fix dataset export conflict with paginated results (#484)

Our front-end uses `from` and `search_after` query params to handle paginated
search results. When a user exports a subset of our complaint database, the
aforementioned pagination params are sent to the API causing it to throw an
error because `from mod size != 0`.

Instead of reworking the API logic it's better to just purge pagination
params from export URLs because they're irrelevant. The whole point of exporting
is to download all the search results and not just a single page of search results.

See https://github.com/cfpb/ccdb5-api/blob/a63efc345e1a652f9c8ec4875e9247aef6f56128/complaint_search/serializer.py#L185-L189
See https://jira/browse/DATAP-33

cypress/e2e/export/export.cy.js

@@ -0,0 +1,34 @@
+describe('Complaint export', () => {
+  const currentPage = '.m-pagination_label';
+  const nextButton = '.m-pagination .m-pagination_btn-next';
+
+  const exportButton = '.export-btn';
+  const filteredDataset = 'label[for=dataset_filtered]';
+  const exportUriInput = '.heres-the-url input';
+
+  beforeEach(() => {
+    let request = '?**&field=all**sort=created_date_desc';
+    let fixture = { fixture: 'list/get-complaints.json' };
+    cy.intercept(request, fixture).as('getComplaints');
+
+    request = '?**&size=0';
+    fixture = { fixture: 'list/get-aggs.json' };
+    cy.intercept('GET', request, fixture).as('getAggs');
+
+    cy.visit('?size=10&searchText=debt%20recovery&tab=List');
+    cy.wait('@getComplaints');
+    cy.wait('@getAggs');
+  });
+
+  it('sends user to an export link without pagination params', () => {
+    cy.get(nextButton).click();
+    cy.url().should('include', 'page=2');
+    cy.get(currentPage).should('have.text', 'Page 2');
+
+    cy.get(exportButton).click();
+    cy.get(filteredDataset).click();
+
+    cy.get(exportUriInput).should('not.include.value', 'frm=');
+    cy.get(exportUriInput).should('not.include.value', 'search_after=');
+  });
+});

src/components/Dialogs/DataExport/dataExportUtils.js

@@ -30,5 +30,9 @@ export function buildSomeResultsUri(format, size, queryState) {
   // eslint-disable-next-line camelcase
   params.no_aggs = true;
 
+  // Remove unnecessary pagination query params
+  delete params.from;
+  delete params.searchAfter;
+
   return API_PLACEHOLDER + stateToQS(params);
 }