Fix extra_vars format and empty value case

[kk-at-redhat]

SUMMARY

For modules inventory, inventory_soruce, group, host and job_template fixed variable, extra_vars and source_vars parameters so that modules while expecting dictionary as an input push values in yaml format into AAP

Also, fixed edge case when user supplies empty dictionary so that yaml value being pushed into AAP is '---'

related #14918 #14842

ISSUE TYPE

• Bug, Docs Fix or other nominal change

COMPONENT NAME

• Collection

AWX VERSION

4.5.2

ADDITIONAL INFORMATION

Suggested testing. (01) Create required objects with no variables/extra_vars (02) Run the following (or similar) tasks

  tasks:
    - ansible.controller.inventory:
        name: "Dynamic A"
        organization: "A"
        variables: {tt: tt, aa: aa}
    
    - ansible.controller.host:
        name: "Host A"
        inventory: "Static A"
        variables: {tt: tt, aa: aa}
    
    - ansible.controller.group:
        name: "Group A"
        inventory: "Static A"
        variables: {tt: tt, aa: aa}

    - ansible.controller.job_template:
        name: "A"
        extra_vars: {tt: tt, aa: aa}

    - ansible.controller.inventory_source:
        name: "A"
        inventory: "Dynamic A"
        source_vars: {tt: tt, aa: aa}

(03) Make sure that variables/extra_vars show right values and formatting in both yaml and json (04) Run the following:

  tasks:
    - ansible.controller.inventory:
        name: "Dynamic A"
        organization: "A"
        variables: {}
    
    - ansible.controller.host:
        name: "Host A"
        inventory: "Static A"
        variables: {}
    
    - ansible.controller.group:
        name: "Group A"
        inventory: "Static A"
        variables: {}

    - ansible.controller.job_template:
        name: "A"
        extra_vars: {}

    - ansible.controller.inventory_source:
        name: "A"
        inventory: "Dynamic A"
        source_vars: {}

(05) Make sure that variables/extra_vars show right values and formatting in both yaml (---) and json ({})