Plugins: Fail plugins installation on wrong args provided (#71355)

* Return error on plugin install extra args

* Remove unused valid argument

* Add log for wrong installation args

pkg/cmd/grafana-cli/commands/install_command_test.go

@@ -0,0 +1,26 @@
+package commands
+
+import (
+	"testing"
+
+	"github.com/grafana/grafana/pkg/cmd/grafana-cli/utils"
+	"github.com/stretchr/testify/require"
+)
+
+func TestValidateInput(t *testing.T) {
+	t.Run("should print message for ignored args", func(t *testing.T) {
+		mockCmdLine := &utils.MockCommandLine{}
+		defer mockCmdLine.AssertExpectations(t)
+
+		cmdArgs := []string{"foo", "bar", "--bar=foo"}
+
+		mockArgs := &utils.MockArgs{}
+		defer mockArgs.AssertExpectations(t)
+
+		mockArgs.On("Len").Return(len(cmdArgs))
+		mockCmdLine.On("Args").Return(mockArgs).Times(1)
+
+		err := validateInput(mockCmdLine)
+		require.EqualError(t, err, "install only supports 2 arguments: plugin and version")
+	})
+}