chore(live): Optimize resource code to recording resource

[deer-hang]

What this PR does / why we need it:

• Optimize some code logic and test cases.
• Improve the content description of the document.
• Add a new field record_slice_duration.

Which issue this PR fixes:
(optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged)
fixes #xxx

Special notes for your reviewer:

Release note:

PR Checklist

• Tests added/passed.

go test -v -coverprofile=coverage_1734347540886_TestAccRecording_basic.cov -coverpkg=./huaweicloud/services/live ./huaweicloud/services/acceptance/live -run TestAccRecording_basic -timeout 360m -parallel 4
=== RUN   TestAccRecording_basic
--- PASS: TestAccRecording_basic (25.16s)
PASS
coverage: 11.2% of statements in ./huaweicloud/services/live
ok      github.com/huaweicloud/terraform-provider-huaweicloud/huaweicloud/services/acceptance/live      25.216s coverage: 11.2% of statements in ./huaweicloud/services/live

• Documentation updated.

• Schema updated.

• CheckDeleted.

  • a. During query operation (Read Context)
    aa. Resource not found
    >>>>>> Paste the screenshot here <<<<<<

  • b. During delete/disassociate/unbind operation (Delete Context)
    ba. Resource not found
    >>>>>> Paste the screenshot here <<<<<<

[github-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This PR has been approved by: @deer-hang

[jinyangyang222]

/lgtm