feat(uat): add T21 and plugin to generate html-documentation

[auarbekov]

Issue #, if available:
add and remove steps for loopback address

Description of changes:

• Add 'I add IP address "ip_address" to loopback interface' step
• Add 'I remove IP address "ip_address" from loopback interface' step
• Add plugin to generate html-documentation from JavaDoc

Why is this change necessary:
Implement scenarios

How was this change tested:
Run scenario on CodeBuild

Test results:

Given my device is registered as a Thing....................................passed
And my device is running Greengrass.........................................passed
When I create a Greengrass deployment with components.......................passed
And I create client device "basic_connect"..................................passed
When I associate "basic_connect" with ggc...................................passed
And I update my Greengrass deployment configuration, setting the component aws.greengrass.clientdevices.Auth configuration to:.passed
And I update my Greengrass deployment configuration, setting the component aws.greengrass.client.Mqtt5JavaSdkClient configuration to:.passed
And I update my Greengrass deployment configuration, setting the component aws.greengrass.clientdevices.IPDetector configuration to:.passed
And I deploy the Greengrass deployment configuration........................passed
Then the Greengrass deployment is COMPLETED on the device after 5 minutes...passed
And the aws.greengrass.clientdevices.mqtt.EMQX log on the device contains the line "is running now!." within 1 minutes.passed
Then I add IP address "127.0.0.2" to loopback interface.....................passed
Then I wait 90 seconds......................................................passed
And I discover core device broker as "default_broker" from "basic_connect" in OTF.passed
And I connect device "basic_connect" on aws.greengrass.client.Mqtt5JavaSdkClient to "default_broker" using mqtt "v5".passed
And I disconnect device "basic_connect" with reason code 0..................passed
Then I remove IP address "127.0.0.2" from loopback interface................passed

Any additional information or context required to review the change:

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[MikeDombo]

Blocked on aws-greengrass/aws-greengrass-testing#220