GET with body results in POST request, potentially overwriting data

[spinscale]

Kibana version: tested on 5.5 and 6.0 branch
Elasticsearch version: see above

Browser version: Chrome

Browser OS version: osx

Description of the problem including expected versus actual behavior: When you accidentally have a GET request (i.e. to get a document, but you left a body below that get request, then your document gets overwritten with this body). I wouldnt expect that from a GET request.

Steps to reproduce:

DELETE foo

PUT foo/bar/1
{
  "foo" : "bar"
}

GET foo/bar/1

# this one writes the document
GET foo/bar/1
{
  "foo" : "bar"
}

Not sure if this a bug or a feature as I suppose that you automatically changing GET to POST when running an operation, at least thats what seems to be look like in the chrome console.

[jbudz]

Reopened by #14032

[jbudz]

Closing as a duplicate of #9963