Copy button for md code blocks (#1902)

Adds a small "copy to clipboard" button in the upper right corner of code blocks in rendered markdown files.
Additionally this removes the trailing lines in such code blocks.

Co-authored-by: Eduard Heimbuch <eduard.heimbuch@cloudogu.com>
Co-authored-by: Matthias Thieroff <matthias.thieroff@cloudogu.com>

gradle/changelog/copy_button.yaml

@@ -0,0 +1,3 @@
+- type: added
+  description: Add copy button for markdown code blocks ([#1902](https://github.com/scm-manager/scm-manager/pull/1902))
+

scm-ui/ui-webapp/public/locales/de/commons.json

@@ -151,6 +151,9 @@
   "importLog": {
     "title": "Importprotokoll"
   },
+  "syntaxHighlighting": {
+    "copyButton": "In die Zwischenablage kopieren"
+  },
   "notifications": {
     "toastTitle": "Benachrichtigung",
     "xMore": "+{{ count }} Benachrichtigung",

scm-ui/ui-webapp/public/locales/en/commons.json

@@ -152,6 +152,9 @@
   "importLog": {
     "title": "Import Log"
   },
+  "syntaxHighlighting": {
+    "copyButton": "Copy to clipboard"
+  },
   "notifications": {
     "toastTitle": "Notification",
     "xMore": "+{{ count }} Notification",