Added pretty print for arrays

[arogachev]

Q	A
Is bugfix?	❌
New feature?	✔️
Breaks BC?	❌
Fixed issues	#18

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Important notes:

• Comments and whitespaces are removed.
• Nesting arrays are supported too.
• Trailing comma is added after the last element.

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Before:

After:

[arogachev]

Here are 2 main reasons for removing of comments:

• https://github.com/nikic/PHP-Parser/issues/791.
• Stuff like this https://github.com/yiisoft/yii2/blob/17aa0e40c1af579ac2ee348ffce59a201185c109/framework/db/pgsql/Schema.php#L94.

But this can be a subject to discuss.