'No Challenges Found' shows up erroneously on challenges page

[ketzjs09]

I notice that whenever I refresh my topcoder.com/challenges page and unless it reloads immediately (which shouldn't be assumed on a global website), I see 'No Challenges Found' (at times for a second or two), only for challenges to then appear.

I think a better UX would be to display something like 'Loading Challenges', while we are awaiting the list to be populated.

Note that when we search and there are no challenges to display, we should still show 'No Challenges Found'