Enable debugging integration tests in VS Code (#2053)

## Changes
This PR adds back debugging functionality that was lost during migration
to `internal.Main` as an entry point for integration tests.

The PR that caused the regression:
https://github.com/databricks/cli/pull/2009. Specifically the addition
of internal.Main as the entrypoint for all integration tests.

## Tests
Manually, by trying to debug a test.

integration/internal/acc/debug.go

@@ -11,14 +11,14 @@ import (
 )
 
 // Detects if test is run from "debug test" feature in VS Code.
-func isInDebug() bool {
+func IsInDebug() bool {
 	ex, _ := os.Executable()
 	return strings.HasPrefix(path.Base(ex), "__debug_bin")
 }
 
 // Loads debug environment from ~/.databricks/debug-env.json.
 func loadDebugEnvIfRunFromIDE(t testutil.TestingT, key string) {
-	if !isInDebug() {
+	if !IsInDebug() {
 		return
 	}
 	home, err := os.UserHomeDir()

integration/internal/main.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"os"
 	"testing"
+
+	"github.com/databricks/cli/integration/internal/acc"
 )
 
 // Main is the entry point for integration tests.
@@ -11,7 +13,7 @@ import (
 // they are not inadvertently executed when calling `go test ./...`.
 func Main(m *testing.M) {
 	value := os.Getenv("CLOUD_ENV")
-	if value == "" {
+	if value == "" && !acc.IsInDebug() {
 		fmt.Println("CLOUD_ENV is not set, skipping integration tests")
 		return
 	}