Change trending hashtags to most used hashtags

[ElJocho]

-> shoud be queried now from frontend with timestamps startdate=now()-24h and enddate=now(). This would reduce undocumented behaviour of endpoint and streamline the behaviour with the interval endpoint.

It will now deliver most used hashtags over all the time without startdate and enddate.

@mrkhan

[ElJocho]

77addc11e701476c6e7e3d2ed1a04f2b1f5512b0