add first Qt6 version of musredit, mupp, etc.

src/musredit_qt6/musredit/icons/edit-copy-plain.svg

@@ -0,0 +1,74 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg
+   xmlns:dc="http://purl.org/dc/elements/1.1/"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns="http://www.w3.org/2000/svg"
+   version="1.1"
+   id="svg3979"
+   height="22"
+   width="22">
+  <defs
+     id="defs3981">
+    <style
+       id="current-color-scheme"
+       type="text/css">
+      .ColorScheme-Text {
+        color:#4d4d4d;
+      }
+      .ColorScheme-Background {
+        color:#eff0f1;
+      }
+      .ColorScheme-Highlight {
+        color:#3daee9;
+      }
+      .ColorScheme-ViewText {
+        color:#31363b;
+      }
+      .ColorScheme-ViewBackground {
+        color:#fcfcfc;
+      }
+      .ColorScheme-ViewHover {
+        color:#93cee9;
+      }
+      .ColorScheme-ViewFocus{
+        color:#3daee9;
+      }
+      .ColorScheme-ButtonText {
+        color:#31363b;
+      }
+      .ColorScheme-ButtonBackground {
+        color:#eff0f1;
+      }
+      .ColorScheme-ButtonHover {
+        color:#93cee9;
+      }
+      .ColorScheme-ButtonFocus{
+        color:#3daee9;
+      }
+      </style>
+  </defs>
+  <metadata
+     id="metadata3984">
+    <rdf:RDF>
+      <cc:Work
+         rdf:about="">
+        <dc:format>image/svg+xml</dc:format>
+        <dc:type
+           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
+        <dc:title></dc:title>
+      </cc:Work>
+    </rdf:RDF>
+  </metadata>
+  <g
+     transform="translate(-601.71428,-517.21933)"
+     id="layer1">
+    <path
+       class="ColorScheme-Text"
+       id="rect4147"
+       transform="translate(601.71428,517.21933)"
+       d="M 4 3 L 4 4 L 4 17 L 5 17 L 7 17 L 8 17 L 8 18 L 8 19 L 14 19 L 18 15 L 18 14 L 18 7 L 18 6 L 16 6 L 16 3 L 15 3 L 5 3 L 4 3 z M 5 4 L 15 4 L 15 6 L 8 6 L 8 7 L 8 16 L 7 16 L 5 16 L 5 4 z M 9 7 L 17 7 L 17 14 L 14 14 L 13 14 L 13 15 L 13 18 L 9 18 L 9 7 z "
+       style="opacity:1;fill:currentColor;fill-opacity:1;stroke:none" />
+  </g>
+</svg>