Improve errors messages in creating Action mode

[mkuziemko]

Description

Changes proposed in this pull request:

• Improve errors messages in creating Action mode

Testing

1. Create cluster with DISABLE_MONITORING_INSTALLATION=true make dev-cluster
2. Build cli make build-tool-cli
3. Create a policy file

   cat > /tmp/policy.yaml << ENDOFFILE
   ;;badsyntax
   ENDOFFILE

4. Create empty parameters file

   cat >/tmp/params.yaml << ENDOFFILE
   ENDOFFILE

5. Try to create a Capact action:

   capact act create cap.interface.automation.concourse.install --name cc  --parameters-from-file /tmp/params.yaml --action-policy-from-file /tmp/policy.yaml

   it will fail with an error:

   Error: while unmarshaling action policy file: error unmarshaling JSON: while decoding JSON: json: cannot unmarshal string into Go value of type graphql.PolicyInput

6. Create an empty policy file

   cat > /tmp/policy.yaml << ENDOFFILE
   ENDOFFILE

7. Create empty parameters file

   cat >/tmp/params.yaml << ENDOFFILE
   {{}badyntax
   ENDOFFILE

8. capact act create cap.interface.automation.concourse.install --name cc  --parameters-from-file /tmp/params.yaml --action-policy-from-file /tmp/policy.yaml

expected error:

Error: while converting YAML action input parameters to JSON: yaml: did not find expected ',' or '}'

I thought about adding UT for this issue but perhaps it is not needed now.

Related issue(s)

• https://github.com/capactio/capact/issues/483