decimal-java 2.0.0

Major changes:

• Minimum Java version raised to Java 17.
  If you need support for older Java versions: version 1.0.2 supports Java 7 and higher.
• The decimal-java library is now modularized, using module name org.firebirdsql.decimal.
• The type org.firebirdsql.decimal.Decimal is now a sealed type.
  As its constructors were package-private, it already was effectively sealed.

Minor changes:

• Upgraded to Gradle 8.1.1
• Upgraded to JUnit 5.9.3
• Replaced "homegrown" hex-parsing with HexFormat
• Some Javadoc cleanup

Also available on Maven:

<dependency>
  <groupId>org.firebirdsql</groupId>
  <artifactId>decimal-java</artifactId>
  <version>2.0.0</version>
</dependency>