Search yaml target file into multiple location

[olblak]

This pr now looks YAML file into multiple locations

if a directory is not defined in the yaml configuration then it checks if the specified file exists on the disk based on the path otherwise search locally from where we run the command

I used the command updatecli diff --config config.yaml on the following config.yaml file to validate

.config.yaml

source:
  kind: dockerDigest
  spec:
    image: "olblak/polls"
    tag: "latest"
targets:
  imageTag:
    name: "updatecli docker image tag"
    kind: "yaml"
    prefix: "olblak/polls@256:"
    spec:
      #path: "/tt"
      #file: "/home/olblak/Project/Jenkins-infra/polls/docker-compose.yaml"
      file: "../../Jenkins-infra/polls/docker-compose.yamli"
      #file: "docker-compose.yamli"
      key: "services.api.image"