Fixes doubles type as &str&str for type:string; format:uuid parameter

[Dema]

Do'not output &str for isString if it is also isUuid

This fixes #10568. Added an "else" clause if it is a string and also an uuid. In this case we shouldn't output &str for string
because is already outputs for uuid. I'm not sure if it is correct way to do it. Maybe it will be better to do
{{#isUuiud}}{{^isString}}&str...

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[wing328]

cc @frol (2017/07) @farcaller (2017/08) @richardwhiuk (2019/07) @paladinzh (2020/05)

[wing328]

LGTM but I've not tested it locally

[JMLX42]

@Dema thank you for this fix! Any reason why UUIDs are not actually typed as Uuid (instead of &str) though?