Factorize getting request parameters
Factorize getting request parameters for both required and non-required ones, by using the function `get_request_parameter` and merging `get_required_request_parameter` into it, with the addition of the parameters "required" and "default".

Use `get_request_parameter` to get the "cursor", "priority" and "all" parameters.
Factorize getting request parameters: Factorize getting request parameters for both required and non-required ones, by using the function `get_request_parameter` and merging `get_required_request_parameter` into it, with the addition of the parameters "required" and "default".

Use `get_request_parameter` to get the "cursor", "priority" and "all" parameters.