internal/logging: Ensure @caller in SDK subsystem logging entries accurately reflects calling code location (#939)

Reference: hashicorp/terraform-plugin-go#179

Previously:

```
2022-04-12T11:11:26.086-0400 [TRACE] provider.terraform-provider-aws: Found data source type: @caller=/Users/bflad/src/github.com/hashicorp/terraform-plugin-sdk/internal/logging/helper_schema.go:21 @module=sdk.helper_schema tf_data_source_type=aws_connect_bot_association timestamp=2022-04-12T11:11:25.917-0400
2022-04-12T11:11:26.086-0400 [TRACE] provider.terraform-provider-aws: Found data source type: @caller=/Users/bflad/src/github.com/hashicorp/terraform-plugin-sdk/internal/logging/helper_schema.go:21 @module=sdk.helper_schema tf_data_source_type=aws_datapipeline_pipeline timestamp=2022-04-12T11:11:25.917-0400
```

Now:

```
2022-04-12T14:54:22.571-0400 [TRACE] provider.terraform-provider-aws: Found data source type: @module=sdk.helper_schema tf_data_source_type=aws_connect_bot_association @caller=/Users/bflad/src/github.com/hashicorp/terraform-plugin-sdk/helper/schema/grpc_provider.go:95 timestamp=2022-04-12T14:54:22.571-0400
2022-04-12T14:54:22.574-0400 [TRACE] provider.terraform-provider-aws: Found data source type: @module=sdk.helper_schema tf_data_source_type=aws_datapipeline_pipeline @caller=/Users/bflad/src/github.com/hashicorp/terraform-plugin-sdk/helper/schema/grpc_provider.go:95 timestamp=2022-04-12T14:54:22.574-0400
```

Author: bflad

.changelog/939.txt

@@ -0,0 +1,7 @@
+```release-note:bug
+helper/resource: Ensured `@caller` in SDK logging entries accurately reflected calling code location
+```
+
+```release-note:bug
+helper/schema: Ensured `@caller` in SDK logging entries accurately reflected calling code location
+```

internal/logging/context.go

@@ -13,7 +13,11 @@ import (
 // already have the root SDK logger and root provider logger setup from
 // terraform-plugin-go tf5server RPC handlers.
 func InitContext(ctx context.Context) context.Context {
-	ctx = tfsdklog.NewSubsystem(ctx, SubsystemHelperSchema, tfsdklog.WithLevelFromEnv(EnvTfLogSdkHelperSchema))
+	ctx = tfsdklog.NewSubsystem(ctx, SubsystemHelperSchema,
+		// All calls are through the HelperSchema* helper functions
+		tfsdklog.WithAdditionalLocationOffset(1),
+		tfsdklog.WithLevelFromEnv(EnvTfLogSdkHelperSchema),
+	)
 
 	return ctx
 }
@@ -30,7 +34,11 @@ func InitTestContext(ctx context.Context, t testing.T) context.Context {
 
 	ctx = tfsdklog.RegisterTestSink(ctx, t)
 	ctx = tfsdklog.NewRootSDKLogger(ctx, tfsdklog.WithLevelFromEnv(EnvTfLogSdk))
-	ctx = tfsdklog.NewSubsystem(ctx, SubsystemHelperResource, tfsdklog.WithLevelFromEnv(EnvTfLogSdkHelperResource))
+	ctx = tfsdklog.NewSubsystem(ctx, SubsystemHelperResource,
+		// All calls are through the HelperResource* helper functions
+		tfsdklog.WithAdditionalLocationOffset(1),
+		tfsdklog.WithLevelFromEnv(EnvTfLogSdkHelperResource),
+	)
 	ctx = TestNameContext(ctx, t.Name())
 
 	return ctx