Add AWS SAM for creating Lambda and API Gateway

[bhavsarpratik]

SAM code for pipeline - zero-shot-classification in zero-shot-classification/sam

• create lambda with name same as pipeline directory
• use the pipeline name ECR registry with container tagged as latest
• use configuration of 2000 RAM and 30 sec timeout
• create API gateway
  • add resource name same as pipeline name
  • add post method to the path /pipeline-name
• add this creation step commands to pipeline github workflow (should create lambda and API if they do not exist)

Kindly test it end2end on your AWS account before creating the PR