Validating absolute DNS name requirement on Static DNS Entry Type

[rimashah25]

What does this PR (Pull Request) do?

• This PR fixes Validate absolute DNS name requirement on StaticDNS CNAME #4743
  It fixes a bug in Traffic_Portal's UI and Traffic_Ops API callback.

Which Traffic Control components are affected by this PR?

• Traffic Portal
• Traffic Ops

What is the best way to verify this PR?

Manual Testing

1. Create a HTTP delivery service
2. Click on More and then add Static DNS entry
3. Select a Type:CNAME_RECORD and type address without a trailing period. On clicking create, you should see an error stating: address must be a valid DNS entry. Missing a trailing period at the end.
4. Once you do add a trailing period, you can create a static DNS entry with a successful message.

Automation Testing

1. Run CIAB
2. Run Traffic_Portal locally (make sure the Traffic_Ops url point to CIAB traffic ops url)
3. Ensure protractor and webdriver-manage are installed.
4. Run webdriver-manager start
5. Run protractor config.js from traffic_control/traffic_portal/test/end-to-end/ folder
6. All 73 specs should pass. 73 specs, 0 failures

If this is a bug fix, what versions of Traffic Control are affected?

• master (d04111c)

The following criteria are ALL met by this PR

• This PR includes tests
• This PR does not include documentation
• This PR includes an update to CHANGELOG.md OR such an update is not necessary
• This PR includes any and all required license headers
• This does not include a database migration
• This PR DOES NOT FIX A SERIOUS SECURITY VULNERABILITY (see the Apache Software Foundation's security guidelines for details)

Additional Information

[mitchell852]

looks good. works well. just some minor comments.

[mitchell852]

also, there are 4 types, right?

are there any rules for TXT_RECORD? if so, want to add it to your tooltip?

[mitchell852]

a couple more places to update the rules.

[ocket8888]

HTML and docs look fine

[mitchell852]

api tests pass, ui tests pass. tested manually. looks good!