/competitions page: Post-transition fixes

[dunkOnIT]

High

• Many reports of the competition date being returned in the wrong locale [Date Range locale fixes #10599]
• [fig 2] Time remaining to comp start not being passed in i18n key
• Search bar reloads after the first character typed, instead of waiting for "Enter"/search trigger

Medium

• Sorting by "By announcement" used to NOT show older and completed competitions. It's no longer the case and it's annoying since few competitions get announced several months back and there's no option to filter out only ongoing and upcoming comps right now
• (fig 1) In Admin View, "Results submitted" date always shows pending, even when results have been posted

Fig 1:

Fig 2: