PG: Add shortcuts for dashboard and watched changes
PG: Add shortcuts for dashboard and watched changes

The original change applied to stable-2.16 [1] wasn't merged properly to
stable-3.0 [2].

[1]: https://gerrit-review.googlesource.com/c/gerrit/+/231393
[2]: https://gerrit-review.googlesource.com/c/gerrit/+/233333/2/polygerrit-ui/app/elements/gr-app.js

Bug: Issue 10166
Change-Id: Iebe7929696f16d30de9309f589521a7c27ca3a69
(cherry picked from commit f43acb58378cd7ac1364f38b2773f73c03cedca3)

qtproject/qtqa-gerrit,qtproject/qtqa-gerrit,qtproject/qtqa-gerrit,GerritCodeReview/gerrit,GerritCodeReview/gerrit,qtproject/qtqa-gerrit,GerritCodeReview/gerrit,GerritCodeReview/gerrit,GerritCodeReview/gerrit,GerritCodeReview/gerrit,qtproject/qtqa-gerrit,qtproject/qtqa-gerrit,qtproject/qtqa-gerrit,GerritCodeReview/gerrit,GerritCodeReview/gerrit