Don't have strings in plugins translatable that [dw]on't work anyhow

The plugin description and -path are not shown translated even if they
are (like for the helloqml plugin and German).
Showing as being translatable gives a wrong impression as examples for
other plugins.
BTW: Those descriptions do translate in the Plugin Editor/Creator's
console log, but only there.
While at it, make helloqml actually work, it apparently had never been
ported from 2.x to 3.x (and later).

Backport of musescore#8985 plus some other random findings (not relevant to the
master branch)

mscore/musescore.cpp

@@ -4312,7 +4312,7 @@ void MuseScore::changeState(ScoreState val)
             "pad-note-256-TAB", "pad-note-512-TAB", "pad-note-1024-TAB", "pad-rest-TAB", "rest-TAB"};
       bool intoTAB = (_sstate != STATE_NOTE_ENTRY_STAFF_TAB) && (val == STATE_NOTE_ENTRY_STAFF_TAB);
       bool fromTAB = (_sstate == STATE_NOTE_ENTRY_STAFF_TAB) && (val != STATE_NOTE_ENTRY_STAFF_TAB);
-      // if activating TAB note entry, swap "pad-note-...-TAB" shorctuts into "pad-note-..." actions
+      // if activating TAB note entry, swap "pad-note-...-TAB" shortcuts into "pad-note-..." actions
       if (intoTAB) {
             for (unsigned i = 0; i < sizeof(stdNames)/sizeof(char*); ++i) {
                   QAction* act = getAction(stdNames[i]);

mscore/shortcut.cpp

@@ -4722,7 +4722,7 @@ void Shortcut::reset()
 //---------------------------------------------------------
 
 static const QString numPadPrefix("NumPad+");
-static const int NUMPADPREFIX_SIZE = 7;         // the length in chars of the above string
+static const int NUMPADPREFIX_SIZE = numPadPrefix.size();
 
 QString Shortcut::keySeqToString(const QKeySequence& keySeq, QKeySequence::SequenceFormat fmt, bool escapeKeyStr /* = false */)
       {

share/plugins/abc_import.qml

@@ -26,7 +26,7 @@ import FileIO 3.0
 MuseScore {
     menuPath: "Plugins.ABC Import"
     version: "3.0"
-    description: qsTr("This plugin imports ABC text from a file or the clipboard. Internet connection is required.")
+    description: "This plugin imports ABC text from a file or the clipboard. Internet connection is required."
     requiresScore: false
     pluginType: "dialog"
 

share/plugins/colornotes.qml

@@ -18,7 +18,7 @@ import MuseScore 3.0
 
 MuseScore {
       version:  "3.5"
-      description: qsTr("This plugin colors notes in the selection depending on their pitch as per the Boomwhackers convention")
+      description: "This plugin colors notes in the selection depending on their pitch as per the Boomwhackers convention"
       menuPath: "Plugins.Notes.Color Notes"
 
       property variant colors : [ // "#rrggbb" with rr, gg, and bb being the hex values for red, green, and blue, respectively

share/plugins/helloqml/helloqml.qml

@@ -5,7 +5,7 @@ import MuseScore 3.0
 MuseScore {
     menuPath:    "Plugins.helloQml"
     version:     "3.0"
-    description: qsTr("This demo plugin shows some basic tasks.")
+    description: "This demo plugin shows some basic tasks."
     pluginType: "dialog"
 
     width:  150
@@ -16,22 +16,22 @@ MuseScore {
         console.log(curScore)
         console.log(score.name)
         var m
-        m = score.firstMeasure()
+        m = score.firstMeasure
         while (m) {
             console.log(qsTr("measure"))
-            var segment = m.first()
+            var segment = m.firstSegment
             while (segment) {
                 var element
                 element = segment.elementAt(0)
                 if (element && element.type == Element.CHORD) {
                     console.log(qsTr("    element"))
                     console.log(element.beamMode)
-                    if (element.beamMode == BeamMode.NO)
+                    if (element.beamMode == Beam.NONE)
                         console.log("  beam no")
                     }
-                segment = segment.next()
+                segment = segment.next
                 }
-            m = m.nextMeasure()
+            m = m.nextMeasure
             }
         }
 
@@ -50,4 +50,3 @@ MuseScore {
             }
         }
     }
-

share/plugins/helloqml/translations/locale_de.ts

@@ -3,11 +3,6 @@
 <TS version="2.0" language="de_DE">
 <context>
     <name>helloqml</name>
-    <message>
-	<location filename="../helloqml.qml" line="8"/>
-        <source>This demo plugin shows some basic tasks.</source>
-        <translation>Dieses Demo-Plugin zeigt einige einfache Funktionen.</translation>
-    </message>
     <message>
 	<location filename="../helloqml.qml" line="13"/>
         <source>hello world</source>

share/plugins/notenames-interactive.qml

@@ -21,8 +21,8 @@ import MuseScore 3.0
 
 MuseScore {
     version: "3.5"
-    description: qsTr("This plugin names notes as per your language setting")
-    menuPath: "Plugins.Notes." + qsTr("Note Names (Interactive)")
+    description: "This plugin names notes as per your language setting"
+    menuPath: "Plugins.Notes." + "Note Names (Interactive)"
     pluginType: "dock"
 
     implicitHeight: controls.implicitHeight * 1.5

share/plugins/notenames.qml

@@ -20,8 +20,8 @@ import MuseScore 3.0
 
 MuseScore {
    version: "3.5"
-   description: qsTr("This plugin names notes as per your language setting")
-   menuPath: "Plugins.Notes." + qsTr("Note Names")
+   description: "This plugin names notes as per your language setting"
+   menuPath: "Plugins.Notes." + "Note Names"
 
    // Small note name size is fraction of the full font size.
    property var fontSizeMini: 0.7;