Backport PR #8212 (#9752)

**Commit 1:**
[state/unhashUrl] use encode-uri-query to generate cleanly encoded urls

By default, the url.format function stringifies the query object and encodes each parameter with `encodeURIComponent()`. This is effective, but does not match the native browser behavior, which is to only encode the non-`pchar` characters as defined by [rfc3986][1]. Because of this, angular's `$location.search()` function uses a function internally called `encodeUriQuery()` to mimic the browser behavior before updating `location.href`.

To bring the same funtionality to the `unhashUrl()` function, the `encodeUriQuery()` was extracted into it's own package and used as the escape handler for `querystring.stringify()`

[1]: https://www.ietf.org/rfc/rfc3986.txt

* Original sha: d9dac3f
* Authored by spalger <spalger@users.noreply.github.com> on 2016-09-09T22:39:57Z

package.json

@@ -94,6 +94,7 @@
     "d3": "3.5.6",
     "elasticsearch": "8.0.1",
     "elasticsearch-browser": "8.0.1",
+    "encode-uri-query": "1.0.0",
     "expiry-js": "0.1.7",
     "exports-loader": "0.6.2",
     "expose-loader": "0.7.0",

src/ui/public/state_management/state_hashing/unhash_url.js

@@ -3,6 +3,12 @@ import {
   format as formatUrl,
 } from 'url';
 
+import encodeUriQuery from 'encode-uri-query';
+
+import {
+  stringify as stringifyQueryString
+} from 'querystring';
+
 import unhashQueryString from './unhash_query_string';
 
 export default function unhashUrl(urlWithHashes, states) {
@@ -26,11 +32,18 @@ export default function unhashUrl(urlWithHashes, states) {
   if (!appUrlParsed.query) return urlWithHashes;
 
   const appQueryWithoutHashes = unhashQueryString(appUrlParsed.query || {}, states);
+
+  // encodeUriQuery implements the less-aggressive encoding done naturally by
+  // the browser. We use it to generate the same urls the browser would
+  const appQueryStringWithoutHashes = stringifyQueryString(appQueryWithoutHashes, null, null, {
+    encodeURIComponent: encodeUriQuery
+  });
+
   return formatUrl({
     ...urlWithHashesParsed,
     hash: formatUrl({
       pathname: appUrlParsed.pathname,
-      query: appQueryWithoutHashes,
+      search: appQueryStringWithoutHashes,
     })
   });
 }