Added MessageIntent for traffic shapping to SMS

[KyleWittAlertMedia]

Fixes

Adds the message intent to the client so that traffic shaping can be used for SMS. Didn't add unit tests as I couldn't find any around this function. If there are some already existing or a pattern you want me to follow, please direct me.

Checklist

• I acknowledge that all my contributions will be made under the project's license
• I have made a material change to the repo (functionality, testing, spelling, grammar)
• I have read the Contribution Guidelines and my PR follows them
• I have titled the PR appropriately
• I have updated my branch with the main branch
• I have added tests that prove my fix is effective or that my feature works
• I have added the necessary documentation about the functionality in the appropriate .md file
• I have added inline documentation to the code I modified

If you have questions, please file a support ticket, or create a GitHub Issue in this repository.

[tiwarishubham635]

These files are auto-generated from the open-api specifications mentioned here. This parameter needs to come from the specification.