azurerm_linux_function_app and azurerm_windows_function_app support for zip_deploy_file

[x-delfino]

PR to add zip_deploy_file to azurerm_linux_function_app and azure_rm_windows_function_app. These changes are based on the existing capabilities available for Web apps so pretty much no new code. I've updated the docs including a small change for the environment variables required for zip deployment both for function apps and web apps.

Tests:

make acctests SERVICE='appservice' TESTARGS='-run=TestAccLinuxFunctionApp_zipDeploy' TESTTIMEOUT='60m'
==> Checking that code complies with gofmt requirements...
==> Checking that Custom Timeouts are used...
==> Checking that acceptance test packages are used...
TF_ACC=1 go test -v ./internal/services/appservice -run=TestAccLinuxFunctionApp_zipDeploy -timeout 60m -ldflags="-X=github.com/hashicorp/terraform-provider-azurerm/version.ProviderVersion=acc"
=== RUN   TestAccLinuxFunctionApp_zipDeploy
=== PAUSE TestAccLinuxFunctionApp_zipDeploy
=== CONT  TestAccLinuxFunctionApp_zipDeploy
--- PASS: TestAccLinuxFunctionApp_zipDeploy (514.32s)
PASS
ok      github.com/hashicorp/terraform-provider-azurerm/internal/services/appservice    514.408s

make acctests SERVICE='appservice' TESTARGS='-run=TestAccWindowsFunctionApp_zipDeploy' TESTTIMEOUT='60m'
==> Checking that code complies with gofmt requirements...
==> Checking that Custom Timeouts are used...
==> Checking that acceptance test packages are used...
TF_ACC=1 go test -v ./internal/services/appservice -run=TestAccWindowsFunctionApp_zipDeploy -timeout 60m -ldflags="-X=github.com/hashicorp/terraform-provider-azurerm/version.ProviderVersion=acc"
=== RUN   TestAccWindowsFunctionApp_zipDeploy
=== PAUSE TestAccWindowsFunctionApp_zipDeploy
=== CONT  TestAccWindowsFunctionApp_zipDeploy
--- PASS: TestAccWindowsFunctionApp_zipDeploy (484.42s)
PASS
ok      github.com/hashicorp/terraform-provider-azurerm/internal/services/appservice    484.518s

[jackofallops]

Thanks @x-delfino - This LGTM 👍

[jackofallops]

Tests look good - Failures are unrelated to the change

[github-actions]

This functionality has been released in v3.50.0 of the Terraform Provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

For further feature requests or bug reports with this functionality, please create a new GitHub issue following the template. Thank you!

[github-actions]

I'm going to lock this pull request because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active contributions.
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