feat(smn): add SMN data-source and resources support.

[WangLiNaruto]

What this PR does / why we need it:

Which issue this PR fixes:
(optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged)
fixes add SMN data-source and resources support.

Special notes for your reviewer:

Release note:

add SMN data-source and resources support.

PR Checklist

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

Acceptance Steps Performed

make testacc TEST="./internal/services/acceptance/smn/"
...
=== RUN   TestAccDatasourceSmnMessageTemplates_basic
--- PASS: TestAccDatasourceSmnMessageTemplates_basic (14.74s)
PASS

=== RUN   TestAccDataTopics_basic
--- PASS: TestAccDataTopics_basic (13.56s)
PASS

=== RUN   TestAccSmnMessageTemplate_basic
--- PASS: TestAccSmnMessageTemplate_basic (11.48s)
PASS

=== RUN   TestAccSMNV2Topic_basic
--- PASS: TestAccSMNV2Topic_basic (17.72s)
PASS

=== RUN   TestAccSMNV2Topic_policies
--- PASS: TestAccSMNV2Topic_policies (27.07s)
PASS

=== RUN   TestAccSMNV2Topic_withEpsID
--- PASS: TestAccSMNV2Topic_withEpsID (11.29s)
PASS

[chengxiangdong]

LGTM