Feeders should support custom definition vars

[KayakinCoder]

Projects will likely need a way to provide it values like analytics-feeder.image_tag and analytics-feeder.stapi_uri, as an example:

name: analytics

lambda:
  ecr_image_uri: "012345678901.dkr.ecr.us-east-1.amazonaws.com/lambdas/analytics-feeder:${analytics-feeder.image_tag}"
  description: "Analytics Feeder lambda"
  env_vars:
    CIRRUS_DATA_BUCKET_NAME: "${CIRRUS_DATA_BUCKET}"
    STAPI_URI: "${analytics-feeder.stapi_uri}"

triggers_sns:
  - topic_arn: "${analytics-feeder.stac_server_post_ingest_sns_topic_arn}"
    filter_policy: |
      {
          "collection": ["collection-1", "collection-2", "collection-3"]
      }

I believe, but am not certain, that this comes into play:

filmdrop-aws-tf-modules/modules/cirrus/feeder_task_workflow.tf

Line 79 in 08167bc

# TODO: Feeders need SSM var support