Introduce elasticsearch.in.bat (i.e. es.in for Windows)

Break-out common functionality between elasticsearch.bat and service.bat
Relates #8237
@costin The shift command on line 40 is what's throwing off the value of `%~dp0`.  Changing this line to `CALL %SCRIPT_DIR%elasticsearch.in.bat` fixes the issue.  I'm just not sure why this wasn't always a problem?