refactor(CFW): change the type of protocols from TypeSet to TypeList in data source CFW service groups

[profoundwu]

What this PR does / why we need it:
change the type of protocols from TypeSet to TypeList in data source CFW service groups
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:

1.  change the type of protocols from TypeSet to TypeList in data source CFW service groups

PR Checklist

• Tests added/passed.
• Documentation updated.
• Schema updated.

Acceptance Steps Performed

make testacc TEST="./huaweicloud/services/acceptance/cfw" TESTARGS="-run TestAccDatasourceServiceGroups_basic"
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./huaweicloud/services/acceptance/cfw -v -run TestAccDatasourceServiceGroups_basic -timeout 360m -parallel 4
=== RUN   TestAccDatasourceServiceGroups_basic
=== PAUSE TestAccDatasourceServiceGroups_basic
=== CONT  TestAccDatasourceServiceGroups_basic
--- PASS: TestAccDatasourceServiceGroups_basic (68.51s)
PASS
ok      github.com/huaweicloud/terraform-provider-huaweicloud/huaweicloud/services/acceptance/cfw       68.567s

[houpeng80]

/lgtm

[Jason-Zhang9309]

/approve

[github-ci-robot]

This PR has been approved by: @Jason-Zhang9309

/approve