This changes the method of rendering list of alert words in DOM,
earlier it was rendered using 'for' loop over the array of alert_words
which is now changed to render using ListWidget, which gets a array
of objects from get_word_list() in alert_words.js.
The use of ListWidget helps to define a parent_container and $container
in table-body of alert-words-table using which we can now apply sorting over
alert words with the help of handle_sort() function in list_widget.js
Changed the method of adding alert_word_settings_item row in table body
through {{#with}} loop because of rendering through ListWidget, which was done
earlier using for loop over each alert-word in while rendering the list.
this commit also mocks template of render_alert_word_item
while mocking ListWidget.create() function in render_alert_words_ui().
and checks that ListWidget.create() is not called when variable `loaded`
is set as false.
Fixes#21142.
"Alert Words" is one of Zulip's oldest settings UI elements, and as a
result is buggy. This commit converts it to use our standard
progressive-table-wrapper system used for settings tables, which has
the side effect of fixing a bug that mad ethe tables look pretty bad
if one adds a very long word.
Fixes#17172.
jai2201
Josh Gilley
Abhishek-Balaji