Inline removal of Gerrit.Nav in Gerrit 3.7

Iabb10c69ffc159baae1062e10ee55dc8fa4ae0a7 removes `getUrlForSearchQuery`
in favor of `search.ts`.
`Gerrit.Nav` is removed by If38fa09e822fe62a54b1c22f6deb70691dbc9d92

This causes the plugin to throws `TypeError: Gerrit.Nav is undefined`
when formatting links to the dependent/needed-by changes. Replace the
removed method by crafting the link directly.

Ref: https://phabricator.wikimedia.org/T355521
Change-Id: I8044242b5e75dd0c3defef591f57b4211e2aff37

gr-zuul/gr-zuul.js

diff --git a/gr-zuul/gr-zuul.js b/gr-zuul/gr-zuul.js
index 89e5527..b6893ce 100644
--- a/gr-zuul/gr-zuul.js
+++ b/gr-zuul/gr-zuul.js
@@ -107,7 +107,7 @@
   }
 
   _computeDependencyUrl(changeInfo) {
-    return Gerrit.Nav.getUrlForSearchQuery(changeInfo.change_id);
+    return `${window.CANONICAL_PATH || ''}/q/${changeInfo.change_id}`;
   }
 
   _isDependsOnSectionVisible() {