Add argument support

[nvima]

Implement Argument Support for httpcli Commands

This commit introduces the ability to pass arguments to httpcli commands,
allowing users to dynamically define values in their configuration files.
With this new feature, users can now provide arguments when invoking httpcli, such as:

httpcli functionname arg1 "arg2 is here" arg3

The changes include:

- Implementing a replaceArgs function that replaces placeholders, such as ${ARG1}, ${ARG2}, etc., in the URL and headers with the respective command line arguments.
- Refactoring the existing environment variable replacement logic into a separate replaceEnvVariables function for better code organization.
- Updating the getJSONData function to accept the new args parameter and call the replaceVariables function, which in turn calls both replaceArgs and replaceEnvVariables.
- Adding a new ReplaceArgs function in the util package to handle argument replacement within the input JSON data.
- Updating Readme