Refactor file loading to detect external modifications and add reload capability

- Extract _load_data() method from load_path() for reuse in reload()
- Add is_extters externally_modified() to track file state changes (mtime/size)
- Replace load_bytes() with load_contents() for better error handling
- Add reload() method to re-read file from disk
- Fix file_state_watcher by properly detecting external changes
- Update TODO list (add Terminal plugin, mark file_state_watcher as fixed)

TODO.md

@@ -3,6 +3,7 @@ ___
 1. Add Godot LSP Client
 1. Add TreeSitter
 1. Add Collapsable code blocks
+1. Add Terminal plugin
 1. Add Plugin to <Shift\><Ctrl\>| and <Ctrl\>| to split views up, down, left, right
 1. Add <Ctrl\>i to **lsp_manager** to list who implements xyz
 
@@ -13,7 +14,6 @@ ___
 
 ___
 ### Fix
-- Fix **file_state_watcher** to prompt refrsh if external changes applied
 - Fix on lsp client unload to close files lsp side and unload server endpoint
 - Fix multi-select <Shift\><Ctrl\> left/right block select movement de-sync
        from leader when '_' in word