Add missing parameters for some POST endpoints

[ghorkov32]

Description

When trying to generate code with oapi-codegen we meet with errors like the following:

Added the missing parameters on PR #325 to fix this and also keep definitions correct

[Ovid]

This is an argument for OpenAI to start using some of these third-party tools to check their OpenAPI spec.

[j-fau]

I found also those missing parameters with swagger-editor :
Semantic error at paths./organization/users/{user_id} Declared path parameter "user_id" needs to be defined within every operation in the path (missing in "post"), or moved to the path-level parameters object Jump to line 5056 Semantic error at paths./organization/projects/{project_id} Declared path parameter "project_id" needs to be defined within every operation in the path (missing in "post"), or moved to the path-level parameters object Jump to line 5242 Semantic error at paths./organization/projects/{project_id}/users/{user_id} Declared path parameter "project_id" needs to be defined within every operation in the path (missing in "post"), or moved to the path-level parameters object Jump to line 5461 Semantic error at paths./organization/projects/{project_id}/users/{user_id} Declared path parameter "user_id" needs to be defined within every operation in the path (missing in "post"), or moved to the path-level parameters object Jump to line 5461