feat(apig): the resource support modifying debugging domain name access

[wuzhuanhong]

What this PR does / why we need it:

The resource supports modifying whether to enable the debug domain name access function.

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:

the resource supports modifying whether to enable the debug domain name access function.
add corresponding documentation and acceptance test.

PR Checklist

• [x] Tests added/passed.
• [x] Documentation updated.
• [x] Schema updated.

Acceptance Steps Performed

make testacc TEST=./huaweicloud/services/acceptance/apig TESTARGS='-run TestAccGroup_DomainAccessEnabled'
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./huaweicloud/services/acceptance/apig -v -run TestAccGroup_DomainAccessEnabled -timeout 360m -parallel 4
=== RUN   TestAccGroup_DomainAccessEnabled
=== PAUSE TestAccGroup_DomainAccessEnabled
=== CONT  TestAccGroup_DomainAccessEnabled
--- PASS: TestAccGroup_DomainAccessEnabled (607.90s)
PASS
ok      github.com/huaweicloud/terraform-provider-huaweicloud/huaweicloud/services/acceptance/apig      608.007s