Full support for other CI/CD services, such as GitLab CI, BitBucket, Jenkins, CircleCI (or manual deploy)

**Is your feature request related to a problem? Please describe.**
I am trying to automate deployment of Azure Static Web Apps from GitLab CI and many of the features available in GitHub do not work. I know that GitHub is a part of Microsoft now, but I do not understand why the Static Web Apps tools were only built for GitHub. Basic deployment from other providers works now but it seems that everything is still tight to GitHub (every build is still looking for GitHub's "event info").

The deployment uses the `StaticSitesClient` (also [swa](https://github.com/Azure/static-web-apps-cli/) is using it) which has no documentation and is closed source. This makes finding issues quite hard.

**Describe the solution you'd like**

Support the following features via the CLI (either StaticSitesClient or https://github.com/Azure/static-web-apps-cli/):
- Pull request/merge request title should be shown when passed via `--pullRequestTitle` (or PR_TITLE). It currently does not show up:
- In the same view when using GitHub you'll get links to your repository / PR and branch. This is also lacking for other platforms.
- It should be able to close/delete an environment. When you try this with StaticSitesClient on other platforms you currently get:
```
The content server has rejected the request with: BadRequest
Reason: Request is missing the pull request id.
```

Also, provide a documentation to the `StaticSitesClient` and ideally the source as well.

**Describe alternatives you've considered**
I have tried to use [swa](https://github.com/Azure/static-web-apps-cli/) and Azure CLI. With `swa` you can also deploy an app but without any branch decoration. With Azure CLI you cannot deploy in any way, but you can delete an environment.

**Additional context**
- See #7 for Azure CLI deployment option
- See #96 for manual deployment