[C] Remove unnecessary memory allocations and minor additions (!1109) · Merge requests · OpenAPI Tools / openapi-generator

Created by: zhemant

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Ran the shell script under ./bin/ to update Petstore sample so that CIs can verify the change. (For instance, only need to run ./bin/{LANG}-petstore.sh and ./bin/security/{LANG}-petstore.sh if updating the {LANG} (e.g. php, ruby, python, etc) code generator or {LANG} client's mustache templates). Windows batch files can be found in .\bin\windows\.
Filed the PR against the correct branch: master, 3.3.x, 4.0.x. Default: master.
Copied the technical committee to review the pull request if your PR is targeting a particular programming language.

added list_create() according to parameters present in the function
modified return type to get compatible to list_t* as a replacement for map
added code for return list of keyValuePair in case of return type map
remove apiClient_free() from test cases and it is already implemented in the functions
fixed issue related to updating with form parameters
added checks in API to avoid seg fault