Support a copy-only PULL model for source control binding

Azure Web Apps has a feature which allows _simple_ manual source control binding, I'd like the same capability in Static Web Apps.

My scenario is that i have a repository directory with **prebuilt** assets, and I **do not want to add/maintain a GitHub action** and Azure credentials in order to copy the files over.

You can see from this bicep snippet how easy it is to bind to a github repo with Web Apps. It would be great to have an equivalent capability in SWA.

```bicep
param repo string = 'https://github.com/Gordonby/AzureAnimated.git'
param repoBranch string = 'master'
resource WebCodeDeploy 'Microsoft.Web/sites/sourcecontrols@2022-03-01' = {
parent: webApplication
name: 'web'
properties: {
repoUrl: repo
branch: repoBranch
isManualIntegration: true
}
}
```