List all expected behaviours for the mandatory parts of the function

[ClaymeCall]

Here's a list of all requirements for the function, that will be converted as unit tests

• Must return the length of whats printed excluding null byte
• Must match the conversion specifiers with the var_list args in the same order
• Must print all types of variables that have a conversion specifier in the struct function_cpl
• Must be able to print all values of the variable type (max int, min int etc...)
• Must print the formats content
• No memory leak

Feel free to add what I forgot so the list is as exhaustive as possible