Follow file symlinks in the UI to their target (#28835)

Symlinks are followed when you click on a link next to an entry, either
until a file has been found or until we know that the link is dead.
When the link cannot be accessed, we fall back to the current behavior
of showing the document containing the target.

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/git/tree_entry_gogit.go

@@ -19,16 +19,12 @@ type TreeEntry struct {
 	gogitTreeEntry *object.TreeEntry
 	ptree          *Tree
 
-	size     int64
-	sized    bool
-	fullName string
+	size  int64
+	sized bool
 }
 
 // Name returns the name of the entry
 func (te *TreeEntry) Name() string {
-	if te.fullName != "" {
-		return te.fullName
-	}
 	return te.gogitTreeEntry.Name
 }
 
@@ -55,7 +51,7 @@ func (te *TreeEntry) Size() int64 {
 	return te.size
 }
 
-// IsSubModule if the entry is a sub module
+// IsSubModule if the entry is a submodule
 func (te *TreeEntry) IsSubModule() bool {
 	return te.gogitTreeEntry.Mode == filemode.Submodule
 }