refactor(components): remove unused import from response-body.jsx

Eliminated the unused `toLower` import from `lodash` in `response-body.jsx`
to clean up the code and improve readability. This change does not affect
the functionality of the component.

src/core/components/response-body.jsx

@@ -1,7 +1,6 @@
 import React from "react"
 import PropTypes from "prop-types"
 import formatXml from "xml-but-prettier"
-import toLower from "lodash/toLower"
 import { extractFileNameFromContentDispositionHeader } from "core/utils"
 import { getKnownSyntaxHighlighterLanguage } from "core/utils/jsonParse"
 import win from "core/window"