Feature request: query-string strip (`pick`, `exclude`)

To eliminate unneeded params, preserve only needed

queryString.strip('http://example.com/?a=1&b=2', [ 'a' ] )
// result : http://example.com/?a=1

It would be helpful when page has many redudant params (like statistic params) and want to get a cleaner one

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Better function names from @Uzlopak:

queryString.pick('http://example.com/?a=1&b=2', [ 'a' ] )
// result : http://example.com/?a=1


queryString.exclude('http://example.com/?a=1&b=2', [ 'a' ] )
// result : http://example.com/?b=2

[Uzlopak]

The python strip equivalent in javacscript would be trim

[sindresorhus]

If anyone wants to work on this, see the initial attempt and feedback in https://github.com/sindresorhus/query-string/pull/261.