Add option to ignore repeated tag markers

When listing tags of a note, this adds the option to only look for tags which contain a single tag marker at the beginning and ignore the others. So if your tag marker is @, and the option is enabled it will display @some_tag as a tag but ignore @@no_tag.

in-note-text-tagging/in-note-text-tagging.qml

@@ -9,6 +9,7 @@ import QOwnNotesTypes 1.0
 
 Script {
     property string tagMarker
+    property bool ignoreDoubleMarkers
     property bool putToBeginning
     property string tagHighlightColor
 
@@ -20,6 +21,13 @@ Script {
             "type": "string",
             "default": "@",
         },
+        {
+            "identifier": "ignoreDoubleMarkers",
+            "name": "Ignore repeated tag markers",
+            "description": "If enabled tags preceded by the same marker multiple times (such as @@no_tag) will be ignored.",
+            "type": "boolean",
+            "default": "false",
+        },
         {
             "identifier": "putToBeginning",
             "name": "Put tags to beginning of note rather than to end",
@@ -129,7 +137,10 @@ Script {
                     
                     // add the tag if it wasn't in the list
                     if (tagNameList.indexOf(tagName) ==  -1) {
-                        tagNameList.push(tagName);
+                        // add the tag if it contains no duplicate tagMarkers or the check is disabled
+                        if(ignoreDoubleMarkers == false || tagName.startsWith(escapeRegExp(tagMarker)) == false) {
+                          tagNameList.push(tagName);
+                        }
                     }
                 }
                 return tagNameList;