Support for exporting to GCloud Functions / Firebase Functions

[kamilafsar]

Before this change you could only create an export for NodeJS. This PR makes makes the export compatible with GCloud Functions / Firebase Functions. Because we now have 2 "flavors" for the export, we added a new flag "--flavor" to the export command.

To create a NodeJS compatible export:

npx phero server export --flavor nodejs

To create a GCloud Functions / Firebase Functions compatible export:

npx phero server export --flavor gcloud-functions

These will output an "export" directory in your project directory. In it, you will find a directory for each service you've defined in your phero.ts file.

To run the NodeJS exported services:

node ./export/helloWorldService/index.js

To deploy a services to Firebase/GCloud, you should run:

gcloud functions deploy helloWorldService 
    --trigger-http 
    --runtime nodejs16 
    --entry-point helloWorldService 
    --source "./export/helloWorldService"

For every service we will export a different bundle. We will of course document all this in docs after release.

[JasperH8g]

Great work, as always 😊

[JasperH8g]

💪