itemactions: Add context menu actions to hide and unhide files using .hidden

Summary:
This patch introduces context menu actions that allow users to hide or unhide selected files by editing the .hidden file in their parent directories.

What this patch does:
- Implemented HideFileItemAction plugin based on KAbstractFileItemActionPlugin
- Plugin is disabled by default unless explicitly enabled in kservicemenurc via the hidefileitemaction key
- "Hide" action adds selected file names to the .hidden file, avoiding duplicates
- "Unhide" action removes selected file names from the .hidden file
- Action visibility logic:
	- If only visible or only hidden files are selected, only the relevant action is shown
	- If both are selected, both "Hide" and "Unhide" actions are shown
- Write permission checks ensure actions are disabled if the .hidden file cannot be modified
- Optimized redundant path computations by calculating parent directory and .hidden file paths once and reusing them

1 files changed, 10 insertions, 0 deletions

diff --git a/src/itemactions/hidefileitemaction.json b/src/itemactions/hidefileitemaction.json
new file mode 100644
index 000000000..7b4627254
--- /dev/null
+++ b/src/itemactions/hidefileitemaction.json
@@ -0,0 +1,10 @@
+{
+    "KPlugin": {
+        "Icon": "hide_table_row",
+        "MimeTypes": [
+            "application/octet-stream"
+        ],
+        "Name": "Hide"
+    },
+    "X-KDE-Show-In-Submenu": true
+}