LibCore+Everywhere: Move SeekMode out of IODevice

Author: https://github.com/alimpfard
Commit: 1ae8775a1b
Pull-request: https://github.com/SerenityOS/serenity/pull/7056

Userland/Libraries/LibCore/IODevice.h

@@ -44,6 +44,12 @@ enum class OpenMode : unsigned {
     MustBeNew = 16,
 };
 
+enum class SeekMode {
+    SetPosition,
+    FromCurrentPosition,
+    FromEndPosition,
+};
+
 AK_ENUM_BITWISE_OPERATORS(OpenMode)
 
 class IODevice : public Object {
@@ -76,12 +82,6 @@ public:
 
     bool can_read() const;
 
-    enum class SeekMode {
-        SetPosition,
-        FromCurrentPosition,
-        FromEndPosition,
-    };
-
     bool seek(i64, SeekMode = SeekMode::SetPosition, off_t* = nullptr);
 
     virtual bool open(OpenMode) = 0;