[#1501] util: Move eACL-to-APE converter to pkg/util

* `ConvertEACLToAPE` is useful method which couldn't be imported
  out of frostfs-node so far as it has been in `internal`
* Since `ConvertEACLToAPE` and related structures and unit-tests
  are placed in `pkg/util`

Signed-off-by: Airat Arifullin <a.arifullin@yadro.com>

cmd/frostfs-cli/modules/util/convert_eacl.go

@@ -6,7 +6,7 @@ import (
 	"git.frostfs.info/TrueCloudLab/frostfs-node/cmd/frostfs-cli/internal/common"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/cmd/frostfs-cli/internal/commonflags"
 	commonCmd "git.frostfs.info/TrueCloudLab/frostfs-node/cmd/internal/common"
-	apeutil "git.frostfs.info/TrueCloudLab/frostfs-node/internal/ape"
+	apeutil "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/ape"
 	"git.frostfs.info/TrueCloudLab/policy-engine/pkg/chain"
 	"github.com/spf13/cobra"
 )