running on openJDK 16

[uxDesign]

I had an issue to get it running and compiling with openJDK 16.

In gradle.build I added options.encoding = 'UTF-8' to gradle.projectsEvaluated to get rid of compile errors with codepage of source files

gradle.projectsEvaluated {
tasks.withType(JavaCompile){
options.compilerArgs << "-Xlint:unchecked"
options.encoding = 'UTF-8'
}
}

and in vicuna.bat of the output I added command line parameter in line 36 to get rid of
Unable to make field private static final long java.awt.Dimension.serialVersionUID accessible: module java.desktop does not "opens java.awt" to unnamed module @643b6bc1

set DEFAULT_JVM_OPTS="--add-opens=java.desktop/java.awt=ALL-UNNAMED"