feat: add messagbird messaging adapter

[olamide203]

What does this PR do?

This PR adds messagebird messging adapter with tests

Test Plan

1. create your messagebird account
2. get your API Key from the messagebird dashboard
3. set up your Virtual mobile number and/or originator from the messagebird dashboard this might require funding your messagebird account.
4. add environment variables and run E2E test.

MESSAGEBIRD_API_KEY="TEST_API_KEY" MESSAGEBIRD_TO="+2347034542344" MESSAGEBIRD_FROM="2347034542344" ./vendor/bin/phpunit tests/e2e/SMS/MessageBirdTest.php

Related PRs and Issues

Closes appwrite/appwrite#6392
Closes #38

Have you read the Contributing Guidelines on issues?

Yes

[gewenyu99]

Hey,

Due to time constraints, I'm going to mark this PR hacktoberfest-accepted for now so you get DO's Hacktoberfest rewards. We'll continue to work with you on this issue for review and merge.

When it is merged, we'll contact you for Appwrite-specific Hacktoberfest swag.

Thanks for helping us improve Appwrite!

[gewenyu99]

Hey there! There were a lot of big PRs during this Hacktoberfest, and we wanted to give everyone ample time to collaborate with our engineering team. If you were able to merge your PRs during October, amazing. If it’s still not merged, don’t worry about it either. Either way, we’ve got your Hacktoberfest swag minted and ready to ship.

Please comment with your Discord username here so we can contact you about your shipping information to deliver your Hacktoberfest swag.