Update headers

Each id was loaded in a separate json, which could lead to IP blocking, so now:

1. added cache to eliminate unnecessary repeated requests,
2. additional requests are formed by 20 ids in a single request,
3. requests now use the session to use cookies.

If the desired number of results <=20, take results from the first json, to avoid blocking captcha

In the realtime_trends function, the maximum number of results is increased to 200

Function realtime_trends - the maximum number of results increased to 64

Corrected description of the 'realtime_trends' function

1. Function 'gtrends' is renamed to 'daily_trends',
2. the 'realtime_trends' function has been added.

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