Make parameters order in a post query configurable

Hi,

has already mention in this issue #1937
I create this issue to speak about technical solution I will PR.

Is your feature request related to a problem? Please describe.

Some API require an exact order of fields in POST multipart formdata.
I the actual behavior the file is always put in first.

Describe the solution you'd like
Make fields order parametable for each request.

To do that, I plan to add in RestRequest an array of 3 Enum value (like ParameterType.File, ParameterType.Body, ParameterType.Post ) which will define the order. (Maybe the enum already exist ? I don't really search for yet )
The default order will be the actual one [File, body, post] to not break existing code.

In the RequestContent.BuildContent I will use this array to re-order call from line 46 to 53 (maybe will add headers in the list also, not sure yet)

Do you thinks this can be a good solution ? Or do you have better idea ?

Describe alternatives you've considered
No work around found

Start by reading RestRequest and RequestContent.BuildContent, especially the parameter handling around lines 46–53, then review issue #1937 for prior context. Determine how the existing [File, body, post] order is represented and how a per-request order could preserve the current default. Done means the requested order is configurable without breaking existing behavior.