[SEIM] Fixes hostName not being passed down for Anomalies table (#45050) (#45075)

## Summary

The router refactor accidentally introduced a bug where anomalies is no longer filtering out entities within the host details and adds a unit test for it.

Before:
<img width="2002" alt="before_anomalies_mixing" src="https://user-images.githubusercontent.com/1151048/64457061-e4060f00-d0ae-11e9-9a2a-29a8bf9be3c4.png">

After: 
<img width="2005" alt="after_no_mixing" src="https://user-images.githubusercontent.com/1151048/64457062-e6686900-d0ae-11e9-81b9-88d19dffb3d2.png">

* https://github.com/elastic/kibana/issues/45038

### Checklist

Use ~~strikethroughs~~ to remove checklist items you don't feel are applicable to this PR.

- [x] This was checked for cross-browser compatibility, [including a check against IE11](https://github.com/elastic/kibana/blob/master/CONTRIBUTING.md#cross-browser-compatibility)
- [x] Any text added follows [EUI's writing guidelines](https://elastic.github.io/eui/#/guidelines/writing), uses sentence case text and includes [i18n support](https://github.com/elastic/kibana/blob/master/packages/kbn-i18n/README.md)
- [x] [Documentation](https://github.com/elastic/kibana/blob/master/CONTRIBUTING.md#writing-documentation) was added for features that require explanation or tutorials
- [x] [Unit or functional tests](https://github.com/elastic/kibana/blob/master/CONTRIBUTING.md#cross-browser-compatibility) were updated or added to match the most common scenarios
- [ ] This was checked for [keyboard-only and screenreader accessibility](https://developer.mozilla.org/en-US/docs/Learn/Tools_and_testing/Cross_browser_testing/Accessibility#Accessibility_testing_checklist)

### For maintainers

- [x] This was checked for breaking API changes and was [labeled appropriately](https://github.com/elastic/kibana/blob/master/CONTRIBUTING.md#release-notes-process)
- [x] This includes a feature addition or change that requires a release note and was [labeled appropriately](https://github.com/elastic/kibana/blob/master/CONTRIBUTING.md#release-notes-process)

x-pack/legacy/plugins/siem/public/pages/hosts/details/__snapshots__/body.test.tsx.snap

@@ -0,0 +1,15 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`body render snapshot 1`] = `
+<Component>
+  <Connect(HostDetailsBodyComponent)
+    detailName="host-1"
+    from={0}
+    isInitializing={false}
+    setQuery={[Function]}
+    to={0}
+  >
+    <Component />
+  </Connect(HostDetailsBodyComponent)>
+</Component>
+`;

x-pack/legacy/plugins/siem/public/pages/hosts/details/body.test.tsx

@@ -0,0 +1,61 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+import { shallow, mount } from 'enzyme';
+import { HostDetailsBody } from './body';
+import React from 'react';
+
+import '../../../mock/ui_settings';
+import { CommonChildren } from '../hosts';
+import toJson from 'enzyme-to-json';
+import { TestProviders } from '../../../mock/test_providers';
+
+describe('body', () => {
+  test('render snapshot', () => {
+    const child: CommonChildren = () => <span>{'I am a child'}</span>;
+    const wrapper = shallow(
+      <TestProviders>
+        <HostDetailsBody
+          children={child}
+          from={0}
+          isInitializing={false}
+          detailName={'host-1'}
+          setQuery={() => {}}
+          to={0}
+        />
+      </TestProviders>
+    );
+    expect(toJson(wrapper)).toMatchSnapshot();
+  });
+
+  test('it should pass expected object properties to children', () => {
+    const child = jest.fn();
+    mount(
+      <TestProviders>
+        <HostDetailsBody
+          children={child}
+          from={0}
+          isInitializing={false}
+          detailName={'host-1'}
+          setQuery={() => {}}
+          to={0}
+        />
+      </TestProviders>
+    );
+
+    // match against everything but the functions to ensure they are there as expected
+    expect(child.mock.calls[0][0]).toMatchObject({
+      endDate: 0,
+      filterQuery: { term: { 'host.name': 'host-1' } },
+      hostName: 'host-1',
+      indexPattern: { fields: [], title: 'auditbeat-*,filebeat-*,packetbeat-*,winlogbeat-*' },
+      kqlQueryExpression: 'host.name: "host-1"',
+      skip: false,
+      startDate: 0,
+      type: 'details',
+    });
+  });
+});

x-pack/legacy/plugins/siem/public/pages/hosts/details/body.tsx

@@ -44,6 +44,7 @@ const HostDetailsBodyComponent = React.memo<HostDetailsBodyComponentProps>(
                 startDate: from,
                 type,
                 indexPattern,
+                hostName: detailName,
                 narrowDateRange: (score: Anomaly, interval: string) => {
                   const fromTo = scoreIntervalToDateTime(score, interval);
                   setAbsoluteRangeDatePicker({