SUP-2264-2: Correct 'unbound variable' on array expansion

[tomowatt]

Misunderstanding by myself on how ${!args[@]} works and missed when locally testing the parameter expansion when there are values in the array in #15

Updated to not substitute args if it is null/empty therefore not producing an empty string, else expand args to give the expect Wiz CLI Parameters. See docs for details:

${parameter:+word}

If parameter is null or unset, nothing is substituted, otherwise the expansion of word is substituted. 

https://www.gnu.org/software/bash/manual/html_node/Shell-Parameter-Expansion.html

Adding a section to gather all the Wiz CLI parameters under for when new ones are added.

[tomowatt]

Tests ran to checking when Parameters are set and not set.

steps:
  - label: "Scan Terraform Files in Directory - with IAC Type"
    command: "cd test-terraform && ls"
    plugins:
      - wiz#SUP-2264-2:
          scan-type: 'iac'
          iac-type: 'Terraform'
          path: 'test-terraform'
  
  - label: "Scan Terraform Files in Directory - without IAC Type"
    command: "cd test-terraform && ls"
    plugins:
      - wiz#SUP-2264-2:
          scan-type: 'iac'
          path: 'test-terraform'

[jeremybumsted]

Love this @tomowatt. I think this is good, but need to update some things to make the linter happy in the build 😄

[tomowatt]

@jeremybumsted rebased my branch now so linter is now happy, but double checking before merging testing worked all good on your side?

[jeremybumsted]

@jeremybumsted rebased my branch now so linter is now happy, but double checking before merging testing worked all good on your side?

@tomowatt Yes - everything looks good from my end too, go ahead and merge!