A modal is added to edit the realm linkifier which
supports ui_report error.
Puppeteer tests to verify linkifier update and an
invalid test to verify that linkifier error messages
are reported on the modal are added as well.
This commit adds `title` attribute and removes
`aria-hidden` attribute in `Delete` button in
linkifiers table.
`aria-hidden` attribute is used only for icons on buttons
that have a plain-text label.
Moved `admin_linkifier_list` template to `/templates/settings/` folder as
earlier, it was inaccurately placed within the `/templates` folder
rather than the `/templates/settings` folder.
akshatdalton
aryanshridhar