Refactor ls-tree and git path related problems (#35858)

Fix #35852, the root problem is that the "name" field is heavily abused
(since #6816, and no way to get a clear fix)

There are still a lot of legacy problems in old code.

Co-authored-by: Giteabot <teabot@gitea.io>

modules/git/tree_entry_gogit_test.go

@@ -0,0 +1,27 @@
+// Copyright 2025 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+//go:build gogit
+
+package git
+
+import (
+	"testing"
+
+	"github.com/go-git/go-git/v5/plumbing/filemode"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestEntryGogit(t *testing.T) {
+	cases := map[EntryMode]filemode.FileMode{
+		EntryModeBlob:    filemode.Regular,
+		EntryModeCommit:  filemode.Submodule,
+		EntryModeExec:    filemode.Executable,
+		EntryModeSymlink: filemode.Symlink,
+		EntryModeTree:    filemode.Dir,
+	}
+	for emode, fmode := range cases {
+		assert.EqualValues(t, fmode, entryModeToGogitFileMode(emode))
+		assert.EqualValues(t, emode, gogitFileModeToEntryMode(fmode))
+	}
+}