Add worker_config with resource tencentcloud_kubernetes_cluster_attachment

[gailwang]

With existing instances test case, the case need an exsting instance, therefor not put it into test file to make auto-tests.

 make testacc TESTARGS=" -run=TestAccTencentCloudTkeAttachExistResource"
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./... -v -run=TestAccTencentCloudTkeAttachExistResource -timeout 120m
?       github.com/terraform-providers/terraform-provider-tencentcloud  [no test files]
testing: warning: no tests to run
PASS
ok      github.com/terraform-providers/terraform-provider-tencentcloud/gendoc  (cached) [no tests to run]
=== RUN   TestAccTencentCloudTkeAttachExistResource
--- PASS: TestAccTencentCloudTkeAttachExistResource (336.47s)
PASS
ok      github.com/terraform-providers/terraform-provider-tencentcloud/tencentcloud     337.703s
?       github.com/terraform-providers/terraform-provider-tencentcloud/tencentcloud/connectivity        [no test files]
?       github.com/terraform-providers/terraform-provider-tencentcloud/tencentcloud/internal/helper     [no test files]
?       github.com/terraform-providers/terraform-provider-tencentcloud/tencentcloud/ratelimit   [no test files]

[gailwang]

original test

make testacc TESTARGS=" -run=TestAccTencentCloudTkeAttachResource"
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./... -v -run=TestAccTencentCloudTkeAttachResource -timeout 120m
?       github.com/terraform-providers/terraform-provider-tencentcloud  [no test files]
testing: warning: no tests to run
PASS
ok      github.com/terraform-providers/terraform-provider-tencentcloud/gendoc  (cached) [no tests to run]
=== RUN   TestAccTencentCloudTkeAttachResource
--- PASS: TestAccTencentCloudTkeAttachResource (353.22s)
PASS
ok      github.com/terraform-providers/terraform-provider-tencentcloud/tencentcloud     354.590s
?       github.com/terraform-providers/terraform-provider-tencentcloud/tencentcloud/connectivity        [no test files]
?       github.com/terraform-providers/terraform-provider-tencentcloud/tencentcloud/internal/helper     [no test files]
?       github.com/terraform-providers/terraform-provider-tencentcloud/tencentcloud/ratelimit   [no test files]