This adds perfectScrollbar to the default streams table
because it currently is inside another perfectScrollbar which
actually makes it impossible to scroll the table normally without
enabling the perfectScrollbar library on this.
Fixes: #6391.
Using weird characters when filtering options items in these various
settings pages would throw exceptions whenever they didn't form a
valid regular expression.
We now wait to load Organization sections until you
click on the section (or virtually click by using arrow
keys).
Some of the sections are coupled in terms of their setup,
so some sections will already be loaded if you had clicked
on a related section.
This changes the layout of "organization settings" for
non-administrators such that they can view "Default streams" ("Actions"
and the form to add new default stream is not visible).
