Add an option to hide link nodes from the list

This adds an hide option to link in and link out in order to be able to hide both from the respective linking list.

packages/node_modules/@node-red/nodes/locales/en-US/common/60-link.html

@@ -22,6 +22,8 @@
     <p>The wires between link nodes are only displayed when a link node is selected.
        If there are any wires to other tabs, a virtual node is shown that can be clicked
        on to jump to the appropriate tab.</p>
+    <p>The link visibility makes it possible to hide links from other flows, or from all
+       other links to provide a better overview.</p>
     <p><b>Note: </b>Links cannot be created going into, or out of, a subflow.</p>
 </script>
 
@@ -34,6 +36,8 @@
     <p>When in 'send to all' mode, the wires between link nodes are only displayed when
        the node is selected. If there are any wires to other tabs, a virtual node
        is shown that can be clicked on to jump to the appropriate tab.</p>
+    <p>The link visibility makes it possible to hide links from other flows, or from all
+       other links to provide a better overview.</p>
     <p><b>Note: </b>Links cannot be created going into, or out of, a subflow.</p>
 </script>
 

packages/node_modules/@node-red/nodes/locales/en-US/messages.json

@@ -179,6 +179,10 @@
         "timeout": "timeout",
         "linkCallType": "Link Type",
         "staticLinkCall": "Fixed target",
+        "visibility": "Visibility",
+        "visibilityGlobal": "Global",
+        "visibilityFlow": "Flow",
+        "visibilityNone": "None",
         "dynamicLinkCall": "Dynamic target (msg.target)",
         "dynamicLinkLabel": "Dynamic",
         "error": {