Adds feature spec for Jira issues list

Tests:
* presence of tabs
* presence of new issue button
* presence of filtered_search_bar
* pagination
  * presence
  * presence of issue values
  * navigation

ee/spec/features/projects/integrations/jira_issues_list_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe 'Jira issues list', :js do
+  include_context 'project integration activation'
+
+  let_it_be(:per_page) { 20 }
+  let_it_be(:public_url) { 'http://jira.foo.bar' }
+  let_it_be(:api_url) { "#{public_url}/api" }
+  let_it_be(:jira_project_key) { 'JIRA-GL1' }
+  let_it_be(:jira_user) { 'JiraGitlabUser' }
+  let_it_be(:timestamp) { Time.current }
+  let_it_be(:jira) do
+    create(
+      :jira_integration,
+      project: project,
+      project_key: jira_project_key,
+      deployment_type: 1,
+      issues_enabled: true,
+      api_url: api_url,
+      url: public_url
+    )
+  end
+
+  context 'when issues#index' do
+    before do
+      stub_licensed_features(jira_issues_integration: true)
+    end
+
+    it 'shows all three tabs' do
+      with_issues 1 do
+        within('div.issuable-list-container') do
+          expect(page).to have_selector('li.nav-item', count: 3, wait: 0)
+        end
+      end
+    end
+
+    it 'has a button to create a new issue in Jira' do
+      with_issues 1 do
+        within('div.issuable-list-container') do
+          link = page.find_link(href: /#{public_url}/, class: 'btn')
+          expect(link.text).to match(/Create new issue in Jira/)
+        end
+      end
+    end
+
+    it 'shows the filtered search bar' do
+      with_issues 10 do
+        expect(page).to have_selector('div[data-testid="filtered-search-input"]')
+      end
+    end
+
+    it 'paginates the list results' do
+      number_of_issues = 35.0
+      number_of_pages = (number_of_issues / per_page).ceil
+
+      with_issues number_of_issues do |issues|
+        expect(all_pages.size).to be(number_of_pages)
+        all_pages.size.times do |page_num|
+          navigate_to_page(page_num)
+
+          offset = per_page * page_num
+
+          aggregate_failures do
+            within('ul.issuable-list') do
+              issues[offset...per_page].each_with_index do |issue, idx|
+                issuable_row = find("li#issuable_#{idx + offset}", wait: 0)
+                expect(issuable_row.text).to include(jira_user)
+                expect(issuable_row.text).to include(issue[:key])
+                expect(issuable_row.text).to include(issue.dig(:fields, :summary))
+                expect(issuable_row.text).to include(issue.dig(:fields, :status, :name))
+                expect(issuable_row.text).to include(issue.dig(:fields, :labels, 0))
+              end
+            end
+          end
+        end
+      end
+    end
+  end
+
+  private
+
+  def all_pages
+    # the first and last navigation items
+    # are Previous, and Next - ignore these.
+    all('ul.pagination li.page-item')[1..-2]
+  end
+
+  def navigate_to_page(page)
+    all_pages[page].click
+  end
+
+  def build_issues(count = 10)
+    (0...count).to_a.map do |idx|
+      build_issue(idx)
+    end
+  end
+
+  def build_issue(idx)
+    {
+      id: idx,
+      key: "#{jira_project_key}-#{idx}",
+      fields: {
+        summary: "Jira issue #{idx}",
+        description: "Jira description #{idx}",
+        created: (timestamp + idx).to_s,
+        updated: (timestamp + idx).to_s,
+        resolutiondate: nil,
+        reporter: {
+          name: jira_user,
+          key: jira_user,
+          emailAddress: "#{jira_user}@gitlab.com",
+          displayName: jira_user,
+          active: true,
+          avatarUrls: { '48x48' => 'foo.jpg' }
+        },
+        labels: ["QA"],
+        status: {
+          description: "Status #{idx}",
+          name: 'In Progress',
+          statusCategory: {
+            colorName: 'yellow',
+            name: 'In Progress'
+          }
+        }
+      }
+    }
+  end
+
+  def with_issues(count)
+    issues = build_issues count
+    stub_issues issues
+    visit project_integrations_jira_issues_path(project)
+    yield issues
+  end
+
+  def stub_issues(issues)
+    body = { startAt: 0, total: issues.size, maxResults: issues.size, issues: issues }
+    stub_request(:get, /\A#{public_url}/)
+      .to_return(headers: { 'Content-Type' => 'application/json' }, body: body.to_json)
+  end
+end