Scenario:
Using github.com/awslabs/aws-lambda-go-api-proxy within github.com/aws/aws-lambda-go/lambda behind an multi_value_headers-enabled ALB

Issue:
URL-Query Parameters can be double-url encoded.
For example a /?from=2022-09-20T04:11:02 would be url-encoded by the browser to /?from=2022-09-20T04%3A11%3A02 (as %3A is the url-encoding of :).
Because of https://github.com/awslabs/aws-lambda-go-api-proxy/blob/master/core/request.go#L164 this value is encoded again before it reaches the handler. Instead of from=2022-09-20T04%3A11%3A02 a double-url encoded value is passed to the handler: from=2022-09-20T04%3A11%253A02 (as %25 is the url-encoding of %).

Suggested solution:
Using url.QueryUnescape before encoding, to see whether the query parameter is already encoded (this would result in err != nil).