fix: disallow file name too long when writing a file (#4881)

* fix: disallow file name too long when writing a file

* bool LongerName to MaxFilenameLength

---------

Co-authored-by: Konstantin Lebedev <9497591+kmlebedev@users.noreply.github.co>

weed/util/fullpath.go

@@ -29,6 +29,13 @@ func (fp FullPath) Name() string {
 	return name
 }
 
+func (fp FullPath) IsLongerFileName(maxFilenameLength uint32) bool {
+	if maxFilenameLength == 0 {
+		return false
+	}
+	return uint32(len([]byte(fp.Name()))) > maxFilenameLength
+}
+
 func (fp FullPath) Child(name string) FullPath {
 	dir := string(fp)
 	noPrefix := name