feat: migrate postdeployment to data http

[glasnt]

Replaces compute engine and associated resources with a data "http" call to the Cloud Run API

Requires moving the logic from the metadata startup scripts to within the containers for placeholder, and a new container for init. Uses the same permissions, only the service account has renamed to reflect the usage.

Merge blocked on:

• updating the containers.tf to reference the latest images (manually created:postjsscurl tagged images used while testing)
• confirming functionality
• removing any compute engine APIs/permissions based on removed resources (without removing infra-required APIs)

Lint issues:

• Warning: data "http" "execute_placeholder_job" is declared but not used (terraform_unused_declarations)
• Warning: data "http" "execute_init_job" is declared but not used (terraform_unused_declarations)
• Warning: variable "zone" is declared but not used (terraform_unused_declarations)

Build failures:

• Cannot delete job 'placeholder-eca5' because there are 1 execution(s) of the job running. (started after reading data.http.execute_placeholder_job)
• Cannot delete job 'init-eca5' because there are 1 execution(s) of the job running. (started after reading data.http.execute_init_job)

[grayside]

Initial questions pass, more a part of design exploration than code review.

[grayside]

Will this exit with a non-zero status code on failure?

[glasnt]

it fires https://github.com/GoogleCloudPlatform/avocano/blob/main/client/docker-deploy.sh so in theory yes, if a failed firebase command returns the correct exit code.

[glasnt]

Closing in favor of #125