feat: add function to move files to bin folder

I've added the move_to_bin_folder function in install.sh.
This function moves a file to the specified destination.
If the destination is not writable, it uses sudo to move the file.
I updated the install_kubectl, install_kind, and install_scaf functions to use the new function.

install.sh

@@ -168,6 +168,17 @@ detect_os_and_arch() {
     echo $os_arch
 }
 
+move_to_bin_folder() {
+    DEST=${2:-$PREFERRED_BIN_FOLDER}
+    echo "Moving $1 to ${DEST}..."
+    # if the DEST folder is not writable, use sudo to move the file
+    if [ -w $DEST ]; then
+        mv $1 $DEST/$1
+    else
+        sudo mv $1 $DEST/$1
+    fi
+}
+
 install_kubectl() {
     echo "Installing kubectl..."
     os_arch=$(detect_os_and_arch)
@@ -179,7 +190,7 @@ install_kubectl() {
             url="https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/${os}/${arch}/kubectl"
             curl -LO $url
             chmod +x ./kubectl
-            sudo mv ./kubectl $PREFERRED_BIN_FOLDER/kubectl
+            move_to_bin_folder ./kubectl
             ;;
         *)
             echo "Unsupported OS or architecture: $os_arch"
@@ -197,7 +208,7 @@ install_kind() {
         "linux-amd64"|"darwin-amd64"|"darwin-arm64"|"linux-arm64"|"windows-amd64")
         curl -Lo ./kind "https://kind.sigs.k8s.io/dl/v0.23.0/kind-$os_arch"
         chmod +x ./kind
-        sudo mv ./kind $PREFERRED_BIN_FOLDER/kind
+        move_to_bin_folder ./kind
         ;;
     *)
         echo "Unsupported OS or architecture: $os_arch"
@@ -221,7 +232,7 @@ install_scaf() {
     if [ -f "$TEMP_DOWNLOAD" ]; then
         chmod +x $TEMP_DOWNLOAD
         echo "Moving scaf to $DESTINATION..."
-        sudo mv $TEMP_DOWNLOAD $DESTINATION
+        move_to_bin_folder $TEMP_DOWNLOAD $DESTINATION
         if [ -f "$DESTINATION" ]; then
             echo "scaf installed successfully at $DESTINATION"
         else