* Ensure that data is not lost when parsing EQL responses

The shared search utilities expect that response data exists in the
response's body field. However, in an EQL response this information also
exists as a sibling to the body field, and so we must normalize this data
into the body before we can leverage these utilities with EQL queries.

* Remove unused EQL parameters

These were previously needed to work around an index resolution but, but
this has since been resolved upstream in elasticsearch via
elastic/elasticsearch#63573.

* Allow custom test subj for Preview Histogram to propagate to DOM

Previously, custom preview histograms were passing a data-test-subj prop
to our general histogram, but the general histogram did not know/care
about this prop and it did not become a data property on the underlying
DOM element. While most of our tests leveraged enzyme, they could still
query by this react prop and everything worked as expected.

However, now that we want to exercise this behavior in cypress, we need
something to propagate to the DOM so that we can determine which
histogram has rendered, so the prop has been updated to be
`dataTestSubj`, which then becomes a data-test-subj on the histogram's
panel. Tests have been updated accordingly.

* Exercise Query Preview during EQL rule creation

* Asserts that the preview displays a histogram
* Asserts that no error toast is displayed

* Add integration tests around EQL sequence signal generation

* Clearer assertion

* Simplify test assertion

* Fix typings

These were updated on an upstream refactor.

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>
# Conflicts:
#	x-pack/plugins/security_solution/cypress/tasks/create_new_rule.ts