Kate: add support for template string syntax of JS

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals

Signed-off-by: Mavridis Philippe <mavridisf@gmail.com>
(cherry picked from commit f7592c53ba)

kate/data/javascript.xml

@@ -101,6 +101,7 @@
 
         <DetectChar attribute="String" context="String" char="&quot;" />
         <DetectChar attribute="String" context="String SQ" char="'" />
+        <DetectChar attribute="String" context="Template String" char="`" />
 
         <IncludeRules context="##Doxygen" />
         <Detect2Chars attribute="Comment" context="Comment" char="/" char1="/" />
@@ -154,6 +155,11 @@
         <LineContinue/>
         <DetectChar attribute="String" context="#pop" char="'" />
       </context>
+      <context attribute="String" lineEndContext="#pop" name="Template String">
+        <HlCStringChar attribute="Char" />
+        <LineContinue/>
+        <DetectChar attribute="String" context="#pop" char="`" />
+      </context>
 
       <context attribute="Comment" lineEndContext="#pop" name="Comment">
         <IncludeRules context="##Alerts" />